MATHWISE ACADEMY
Grade 8 Mathematics: Test 1 • Chapter 1: Whole Numbers
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Calculators may NOT be used for Question 1 and Question 2. A non-programmable calculator may be used for Questions 3, 4, and 5 unless stated otherwise.
- Round off final answers to two decimal places where necessary, unless specified otherwise.
- Write neatly and legibly.
QUESTION 1: PROPERTIES AND OPERATIONS [10]
(Note: No calculators permitted for this question)
1.1 Calculate the value of the following using the correct order of operations:
1.2 Use the distributive property to calculate the product without a calculator:
1.3 State the mathematical property demonstrated in each statement below:
- 1.3.1 \( 14 + (26 + 9) = (14 + 26) + 9 \) (1)
- 1.3.2 \( 45 \times 12 = 12 \times 45 \) (1)
1.4 State whether each statement is TRUE or FALSE:
- 1.4.1 \( 0 \) is the identity element for multiplication. (1)
- 1.4.2 \( 15 \div 0 \) is undefined. (1)
- 1.4.3 The set of natural numbers \( \mathbb{N} \) contains the number \( 0 \). (1)
QUESTION 2: PRIME FACTORS, HCF AND LCM [10]
(Note: No calculators permitted for this question)
2.1 Express the following numbers as products of their prime factors using exponential form:
- 2.1.1 \( 72 \) (2)
- 2.1.2 \( 120 \) (2)
2.2 Using your prime factorizations from Question 2.1:
- 2.2.1 Determine the Highest Common Factor (HCF) of \( 72 \) and \( 120 \). (2)
- 2.2.2 Determine the Lowest Common Multiple (LCM) of \( 72 \) and \( 120 \). (2)
2.3 Two large numbers are decomposed into prime factors:
\( B = 2^2 \times 3^4 \times 7^1 \)
Write down the HCF of numbers \( A \) and \( B \) as a product of prime factors.
QUESTION 3: RATIOS AND RATES [10]
3.1 Simplify the following ratios to their simplest form:
- 3.1.1 \( 45\text{ cm} : 1,5\text{ m} \) (2)
- 3.1.2 \( 0,4 : 0,16 \) (2)
3.2 Divide \( \text{R } 720 \) among Adam, Brian, and Caleb in the ratio \( 2 : 3 : 5 \).
3.3 A car travels a distance of \( 325\text{ km} \) in \( 2\text{ hours and } 30\text{ minutes} \) at a constant speed.
- 3.3.1 Calculate the speed of the car in \( \text{km/h} \). (1)
- 3.3.2 At this same speed, how long (in hours) will it take the car to travel \( 520\text{ km} \)? (2)
QUESTION 4: CURRENCY AND PERCENTAGES [10]
4.1 The exchange rate between the South African Rand and the US Dollar is \( \$1 = \text{R } 14,80 \).
- 4.1.1 An online textbook costs \( \$35 \). Calculate its cost in South African Rands. (1)
- 4.1.2 Sipho has \( \text{R } 1\,110 \) to exchange for US Dollars before travelling. How many Dollars will he receive? (2)
4.2 A store purchases a school bag for \( \text{R } 240 \) and adds a markup profit of \( 35\% \). Calculate the selling price of the bag.
4.3 During a clearance sale, a jacket is sold for \( \text{R } 420 \) after a \( 25\% \) discount was deducted from the original price. Determine the original marked price of the jacket before discount.
4.4 In a mathematics test out of \( 60 \), Lerato scored \( 51 \) marks. Calculate her percentage score.
QUESTION 5: SIMPLE INTEREST AND HIRE PURCHASE [10]
5.1 Kagiso invests \( \text{R } 8\,000 \) in a savings account earning \( 7,5\% \) per annum simple interest for \( 4 \) years.
- 5.1.1 Calculate the total simple interest earned over the \( 4 \) years. (2)
- 5.1.2 Calculate the accumulated total value of the investment at the end of the term. (1)
5.2 Nomsa buys a computer system with a cash price of \( \text{R } 15\,000 \) on a hire purchase agreement. She pays a \( 20\% \) cash deposit upfront and finances the remaining balance over \( 3 \) years at a simple interest rate of \( 15\% \) per annum.
- 5.2.1 Calculate the deposit amount paid in Rands. (1)
- 5.2.2 Calculate the loan balance owed after paying the deposit. (1)
- 5.2.3 Calculate the total simple interest charged on the loan balance over the \( 3 \) years. (2)
- 5.2.4 Determine the total amount payable on the hire purchase agreement (including deposit). (1)
- 5.2.5 Calculate Nomsa's fixed monthly repayment installment. (2)
MATHWISE ACADEMY
Grade 8 Mathematics: Test 2 • Chapter 1: Whole Numbers
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Calculators may NOT be used for Question 1 and Question 2. A non-programmable calculator may be used for Questions 3, 4, and 5 unless stated otherwise.
- Round off final answers to two decimal places where necessary, unless specified otherwise.
- Write neatly and legibly.
QUESTION 1: PROPERTIES AND OPERATIONS [10]
(Note: No calculators permitted for this question)
1.1 Calculate the value of the following using the correct order of operations:
1.2 Use the distributive property to calculate the product without a calculator:
1.3 Name the mathematical property demonstrated in each statement below:
- 1.3.1 \( (15 + 7) + 3 = 15 + (7 + 3) \) (1)
- 1.3.2 \( 29 \times 1 = 29 \) (1)
1.4 State whether each statement is TRUE or FALSE:
- 1.4.1 Division is a commutative operation. (1)
- 1.4.2 \( 12 \div 0 = 0 \) (1)
- 1.4.3 Subtraction is the inverse operation of addition. (1)
QUESTION 2: PRIME FACTORS, HCF AND LCM [10]
(Note: No calculators permitted for this question)
2.1 Express the following numbers as products of their prime factors using exponential form:
- 2.1.1 \( 90 \) (2)
- 2.1.2 \( 126 \) (2)
2.2 Using your prime factorizations from Question 2.1:
- 2.2.1 Determine the Highest Common Factor (HCF) of \( 90 \) and \( 126 \). (2)
- 2.2.2 Determine the Lowest Common Multiple (LCM) of \( 90 \) and \( 126 \). (2)
2.3 A certain natural number is a factor of \( 45 \), is less than \( 45 \), and is divisible by \( 3 \) but not by \( 9 \).
What is this number? (Show your reasoning).
QUESTION 3: RATIOS AND RATES [10]
3.1 Simplify the following ratio to its simplest form:
3.2 Determine the missing value in the following equivalent ratio:
3.3 Divide \( \text{R } 1\,200 \) among three partners in the ratio \( 3 : 4 : 5 \).
3.4 A water pump can fill a \( 4\,500\text{-litre} \) JoJo tank from empty in \( 15\text{ minutes} \).
- 3.4.1 Calculate the pumping rate in litres per minute (\( \text{l/min} \)). (1)
- 3.4.2 At this same rate, how long (in minutes) will it take to fill a \( 1\,800\text{-litre} \) tank? (2)
QUESTION 4: CURRENCY AND PERCENTAGES [10]
4.1 The exchange rate between the South African Rand and the British Pound is \( £1 = \text{R } 21,50 \).
- 4.1.1 Khanya has \( \text{R } 3\,225 \) saved. How many British Pounds will she receive if she exchanges her money? (2)
- 4.1.2 You buy a book online for \( £18 \). Calculate the cost in South African Rands. (1)
4.2 A merchant buys a pair of sneakers for \( \text{R } 600 \) and sells them at a profit of \( 30\% \). Calculate the selling price of the sneakers.
4.3 During a "Back to School" sale, a bicycle is sold for \( \text{R } 1\,440 \) after a \( 20\% \) discount was applied. Determine the original marked price of the bicycle before the discount.
4.4 In a natural sciences project, David scored \( 45 \) out of \( 75 \). Calculate his percentage score.
QUESTION 5: SIMPLE INTEREST AND HIRE PURCHASE [10]
5.1 Thabo invests \( \text{R } 12\,000 \) at a simple interest rate of \( 8,5\% \) per annum for \( 5 \) years.
- 5.1.1 Calculate the total simple interest earned over the \( 5 \) years. (2)
- 5.1.2 Calculate the final accumulated value of the investment. (1)
5.2 An electronics store sells a smart TV for \( \text{R } 8\,500 \). A customer buys it on a hire purchase agreement. They pay a \( 10\% \) cash deposit upfront and pay off the balance over \( 2 \) years at \( 12\% \) per annum simple interest.
- 5.2.1 Calculate the deposit amount paid. (1)
- 5.2.2 Calculate the loan balance to be financed after the deposit is paid. (1)
- 5.2.3 Calculate the total simple interest charged on the loan balance over the \( 2 \) years. (2)
- 5.2.4 Determine the total amount payable on the loan (excluding the deposit). (1)
- 5.2.5 Calculate the fixed monthly repayment installment. (2)
MATHWISE ACADEMY
Grade 8 Mathematics: Test 1 • Integers, Exponents, Patterns, and Functions
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Calculators may NOT be used for Question 1 and Question 2. A non-programmable calculator may be used for Questions 3 and 4.
- Write neatly and legibly.
QUESTION 1: INTEGERS [12]
(Note: No calculators permitted for this question)
1.1 Calculate the value of the following without using a calculator:
- 1.1.1 \( -8 + (-5) - (-12) \) (2)
- 1.1.2 \( (-3) \times (+4) \div (-2) \) (2)
1.2 Evaluate the following:
1.3 The temperature in Centurion drops from \( 5^\circ\text{C} \) by \( 12^\circ\text{C} \) overnight. Calculate the new temperature.
1.4 Replace the \( * \) with \( > \), \( < \), or \( = \) to make the statement true:
1.5 Arrange the following list of integers in descending order (from largest to smallest):
QUESTION 2: EXPONENTS [13]
(Note: No calculators permitted for this question)
2.1 Simplify the following using the laws of exponents. Leave your answers in exponential form where applicable:
- 2.1.1 \( x^3 \times x^4 \times x \) (2)
- 2.1.2 \( \dfrac{2^8 \times 3^5}{2^5 \times 3^4} \) (3)
2.2 Simplify the following expression:
2.3 Simplify the following, showing all your steps:
2.4 Calculate the final value of the following expression:
QUESTION 3: NUMERIC AND GEOMETRIC PATTERNS [13]
3.1 Consider the following number sequence:
- 3.1.1 Write down the next two terms in the sequence. (2)
- 3.1.2 State the rule for this sequence in words. (2)
- 3.1.3 Determine the general rule for the \( n\text{-th} \) term (\( T_n \)) of the sequence. (2)
- 3.1.4 Use your rule to calculate the value of the \( 40^{\text{th}} \) term. (2)
- 3.1.5 Which term in the sequence is equal to \( 87 \)? (2)
3.2 Consider the number pattern:
- 3.2.1 What is the constant ratio for this sequence? (1)
- 3.2.2 Write down the next two terms. (2)
QUESTION 4: FUNCTIONS AND RELATIONSHIPS [12]
4.1 The rule for finding \( y \) is given by the equation \( y = -3x + 4 \).
Determine the output values (\( y \)) for the input values \( x \in \{-2; 0; 5\} \).
4.2 Determine the input value (\( x \)) if the output value (\( y \)) is \( -17 \) for the rule \( y = 4x - 1 \).
4.3 The input (\( x \)) and output (\( y \)) values of a function are given in the table below:
| \( x \) | \( 1 \) | \( 2 \) | \( 3 \) | \( 4 \) | \( 10 \) |
|---|---|---|---|---|---|
| \( y \) | \( 1 \) | \( 4 \) | \( 7 \) | \( 10 \) | \( ? \) |
- 4.3.1 Determine the algebraic rule for this function in the form \( y = \dots \) (2)
- 4.3.2 Calculate the missing \( y \)-value when \( x = 10 \). (2)
4.4 A flow diagram takes an input \( n \), applies the rule \( (n \div 2) + 5 \), and produces an output \( p \).
Calculate the value of \( p \) if \( n = 12 \).
MATHWISE ACADEMY
Grade 8 Mathematics: Test 2 • Integers, Exponents, Patterns, and Functions
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Calculators may NOT be used for Question 1 and Question 2. A non-programmable calculator may be used for Questions 3 and 4.
- Write neatly and legibly.
QUESTION 1: INTEGERS [12]
(Note: No calculators permitted for this question)
1.1 Calculate the value of the following using the correct order of operations:
1.2 Use the commutative and associative properties of multiplication to calculate the following:
1.3 Substitute the given values and evaluate the expression:
If \( x = -2 \) and \( y = -3 \), calculate the value of \( x^2 - y^2 \).
1.4 A student's bank account is overdrawn and has a balance of \( -\text{R } 150 \).
The student makes a deposit of \( \text{R } 400 \), followed by a withdrawal of \( \text{R } 320 \). Calculate the final balance of the bank account. Show your calculation.
QUESTION 2: EXPONENTS [13]
(Note: No calculators permitted for this question)
2.1 Simplify the following algebraic expressions. Leave your answers with positive exponents:
- 2.1.1 \( (2x^3y^2)(-3x^2y^4) \) (3)
- 2.1.2 \( \dfrac{15a^6b^3}{-3a^2b^3} \) (3)
2.2 Evaluate the following expression:
2.3 Calculate the final value of the following:
2.4 Solve for \( x \) by inspection:
QUESTION 3: NUMERIC AND GEOMETRIC PATTERNS [13]
3.1 Consider the following number sequence:
- 3.1.1 Write down the next two terms in the sequence. (2)
- 3.1.2 Determine the general rule for the \( n\text{-th} \) term (\( T_n \)) of the sequence. (2)
- 3.1.3 Calculate the value of the \( 50^{\text{th}} \) term. (2)
3.2 Consider the following geometric number pattern:
- 3.2.1 State the constant ratio for this sequence. (1)
- 3.2.2 Write down the next term in the sequence. (1)
3.3 A pattern of small squares is constructed using matches:
- 3.3.1 How many matches will be required to build Pattern 4? (1)
- 3.3.2 Determine the rule (\( T_n \)) for the number of matches used in Pattern \( n \). (2)
- 3.3.3 Which pattern number will be constructed using exactly \( 61 \) matches? (2)
QUESTION 4: FUNCTIONS AND RELATIONSHIPS [12]
4.1 A flow diagram takes an input value, multiplies it by \( -3 \), and then adds \( 5 \) to produce the output \( y \).
Determine the output values (\( y \)) for the input values \( x \in \{-2; 0; 4\} \).
4.2 The relationship between \( x \) and \( y \) is given by the formula: \( y = \dfrac{x}{2} - 4 \).
- 4.2.1 Calculate the output if the input is \( x = -6 \). (2)
- 4.2.2 Calculate the input \( x \) if the output is \( y = 1 \). (2)
4.3 The input (\( x \)) and output (\( y \)) values of a function are given in the table below:
| \( x \) | \( 1 \) | \( 2 \) | \( 3 \) | \( 4 \) |
|---|---|---|---|---|
| \( y \) | \( -1 \) | \( 1 \) | \( 3 \) | \( 5 \) |
Determine the algebraic rule for this function in the form \( y = \dots \)
4.4 The formula for a specific function is given as \( y = x^2 - 3x \).
Calculate the value of \( y \) when \( x = -4 \).
MATHWISE ACADEMY
Grade 8 Mathematics: Test 1 • Algebraic Expressions and Equations
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Write neatly and legibly.
QUESTION 1: ALGEBRAIC EXPRESSIONS - BASICS & SUBSTITUTION [10]
1.1 Consider the algebraic expression: \( 4x^2 - 5x + 8 \)
- 1.1.1 How many terms are in this expression? (1)
- 1.1.2 Write down the constant term. (1)
- 1.1.3 State the coefficient of \( x \). (1)
1.2 Evaluate the following expression if \( a = -2 \) and \( b = 3 \):
1.3 Write down an algebraic expression for each of the following statements:
- 1.3.1 Four more than three times a certain number \( x \). (1)
- 1.3.2 The square of the product of \( x \) and \( y \). (2)
QUESTION 2: SIMPLIFYING ALGEBRAIC EXPRESSIONS [13]
2.1 Simplify the following algebraic expressions:
- 2.1.1 \( 3a^2b - 5ab^2 - 7a^2b + 2ab^2 \) (3)
- 2.1.2 \( -3x(2x - 5) - (2x^2 - 3x) \) (4)
- 2.1.3 \( \dfrac{15x^3 - 10x^2}{5x} \) (3)
2.2 Determine the simplified answer for the following:
QUESTION 3: ALGEBRAIC EQUATIONS [15]
3.1 Solve the following equations for \( x \). Show all your steps clearly:
- 3.1.1 \( 3x - 5 = 16 \) (2)
- 3.1.2 \( 5x - 2 = 6 + 4x \) (3)
- 3.1.3 \( 7(x + 2) = 6(x + 1) \) (4)
- 3.1.4 \( \dfrac{2x}{3} = 4 \) (3)
3.2 Solve the following exponential equation for \( x \):
QUESTION 4: PROBLEM SOLVING WITH ALGEBRA [12]
4.1 The sum of three consecutive odd numbers is \( 39 \).
Set up an equation and determine the three numbers.
4.2 The length of a rectangle is \( 5\text{ cm} \) more than its breadth. The perimeter of the rectangle is \( 38\text{ cm} \).
Calculate the length and the breadth of the rectangle.
4.3 Jason states that \( x = -1 \) is the solution to the following equation:
Show whether Jason is correct or incorrect by evaluating both sides of the equation.
MATHWISE ACADEMY
Grade 8 Mathematics: Test 2 • Algebraic Expressions and Equations
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Write neatly and legibly.
QUESTION 1: ALGEBRAIC EXPRESSIONS - BASICS & SUBSTITUTION [10]
1.1 Consider the algebraic expression: \( 3x^3 - 5x^2y + 4xy - 7 \)
- 1.1.1 How many terms are in this algebraic expression? (1)
- 1.1.2 Write down the constant term. (1)
- 1.1.3 State the coefficient of the \( x^2y \) term. (1)
1.2 Evaluate the following expression if \( a = -1 \) and \( b = 2 \):
1.3 Write down an algebraic expression for each of the following statements:
- 1.3.1 The square root of the sum of \( x \) and \( y \). (1)
- 1.3.2 Subtract the product of \( 4 \) and \( x \) from \( 10 \). (2)
QUESTION 2: SIMPLIFYING ALGEBRAIC EXPRESSIONS [12]
2.1 Simplify the following algebraic expressions:
- 2.1.1 \( 5a^2b - 3ab^2 - 2a^2b + 7ab^2 \) (2)
- 2.1.2 \( (-3x^2y)(-4xy^3) \) (2)
- 2.1.3 \( -2x(3x^2 - 4x + 1) - x(x^2 - 3x) \) (4)
- 2.1.4 \( \dfrac{12x^4y^3 - 8x^3y^2}{-4x^2y} \) (4)
QUESTION 3: ALGEBRAIC EQUATIONS [15]
3.1 Solve the following equations for \( x \). Show all your steps clearly:
- 3.1.1 \( 4x - 7 = 13 \) (2)
- 3.1.2 \( 2(3x - 1) = 4x + 6 \) (4)
- 3.1.3 \( \dfrac{3x}{4} - 2 = 7 \) (3)
- 3.1.4 \( 4x - (x - 2) = 5 - 2x \) (3)
3.2 Solve the following exponential equation for \( x \):
QUESTION 4: PROBLEM SOLVING WITH ALGEBRA [13]
4.1 A mother is \( 30 \) years older than her daughter. In \( 5 \) years' time, the mother will be \( 3 \) times as old as her daughter.
Let the daughter's current age be \( x \). Set up an equation and calculate their current ages.
4.2 The length of a rectangle is twice its breadth. The perimeter of the rectangle is \( 48\text{ cm} \).
Calculate the length and the breadth of the rectangle.
4.3 A man bought \( 5 \) pens and \( 3 \) notebooks. A notebook costs \( \text{R } 10 \) more than a pen.
If he paid \( \text{R } 150 \) in total, what is the cost of one pen?
MATHWISE ACADEMY
Grade 8 Mathematics: Test 1 • Common Fractions, Decimal Fractions, and Graphs
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- You may NOT use a calculator for Question 1 and Question 2.
- Write neatly and legibly.
QUESTION 1: COMMON FRACTIONS [17]
(Note: No calculators permitted for this question)
1.1 Calculate the following and leave your answer in its simplest form. Show all steps:
- 1.1.1 \( \dfrac{3}{4} - \dfrac{1}{6} + \dfrac{2}{3} \) (3)
- 1.1.2 \( 2\dfrac{1}{2} \times 1\dfrac{1}{3} \) (3)
- 1.1.3 \( 3\dfrac{1}{3} \div 4\dfrac{2}{5} \) (3)
1.2 Calculate the following, applying the correct order of operations:
1.3 Rewrite the improper fraction \( \dfrac{23}{5} \) as a mixed number.
1.4 Calculate \( \dfrac{5}{6} \) of \( \text{R } 360 \).
QUESTION 2: DECIMAL FRACTIONS [17]
(Note: No calculators permitted for this question)
2.1 Write \( 0,075 \) as a common fraction in its simplest form.
2.2 Round off \( 14,896 \) to two decimal places.
2.3 Calculate the following without a calculator. Show your working clearly:
- 2.3.1 \( 12,45 + 3,8 - 5,09 \) (3)
- 2.3.2 \( 0,4 \times 0,12 \) (2)
- 2.3.3 \( 24,5 \div 0,7 \) (3)
2.4 Calculate the following directly:
2.5 A car travels \( 12,5\text{ km} \) on a single litre of petrol.
How far will the car travel on \( 4,2\text{ litres} \) of petrol?
QUESTION 3: GRAPHS [16]
3.1 Consider the Cartesian plane:
- 3.1.1 Write down the coordinates of a point \( P \) if it starts at the origin, translates \( 4 \) units left, and then \( 3 \) units up. (2)
- 3.1.2 In which quadrant does the point \( R(5 ; -2) \) lie? (1)
3.2 A plumber charges a fixed call-out fee of \( \text{R } 150 \) and an additional \( \text{R } 60 \) per hour of work. The cost \( C \) (in Rands) can be represented by the equation \( C = 150 + 60h \), where \( h \) is the number of hours worked.
- 3.2.1 If a graph were drawn to represent this equation, would the data be considered discrete or continuous? Explain your answer briefly. (2)
- 3.2.2 Calculate the total cost for \( 4 \) hours of work. (2)
- 3.2.3 If the plumber's total bill is \( \text{R } 450 \), calculate how many hours the plumber worked. (3)
3.3 The temperature \( T \) (\(\text{in } ^\circ\text{C}\)) of a room is recorded over a day. It starts at \( 10^\circ\text{C} \) at 06:00, rises steadily to a maximum of \( 25^\circ\text{C} \) at 14:00, stays constant until 15:00, and then drops steadily to \( 18^\circ\text{C} \) at 18:00.
- 3.3.1 What is the maximum temperature recorded during this period? (1)
- 3.3.2 During which specific time interval is the temperature increasing? (2)
- 3.3.3 During which specific time interval is the temperature constant? (1)
- 3.3.4 If you were to draw this graph, would the trend line from 15:00 to 18:00 be linear or non-linear? Give a reason for your answer based on the description. (2)
MATHWISE ACADEMY
Grade 8 Mathematics: Test 2 • Common Fractions, Decimal Fractions, and Graphs
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- You may NOT use a calculator for Question 1 and Question 2.
- Write neatly and legibly.
QUESTION 1: COMMON FRACTIONS [16]
(Note: No calculators permitted for this question)
1.1 Calculate the following and leave your answers in their simplest form. Show all steps:
- 1.1.1 \( 1\dfrac{1}{4} + \dfrac{2}{3} \times \dfrac{9}{8} \) (4)
- 1.1.2 \( 3\dfrac{1}{2} \div 1\dfrac{1}{6} \) (3)
1.2 Calculate the following, showing all your working:
1.3 A shopkeeper decides to increase the price of a bicycle, which currently costs \( \text{R } 450 \), by \( 20\% \).
Calculate the new price of the bicycle.
1.4 Express \( 12\dfrac{1}{2}\% \) as a common fraction in its simplest form.
QUESTION 2: DECIMAL FRACTIONS [17]
(Note: No calculators permitted for this question)
2.1 Write \( \dfrac{7}{8} \) as a decimal fraction.
2.2 Round off \( 34,865 \) to one decimal place.
2.3 Calculate the following without a calculator. Show your working clearly:
- 2.3.1 \( 0,4 \times 0,12 \times 100 \) (3)
- 2.3.2 \( 12,5 \div 0,05 \) (3)
2.4 Calculate the following directly:
2.5 A delivery truck uses \( 6,5\text{ litres} \) of fuel to travel \( 100\text{ km} \).
Calculate how many litres of fuel the truck will use to travel \( 350\text{ km} \).
QUESTION 3: GRAPHS [17]
3.1 Consider the equation \( y = 3x - 4 \):
- 3.1.1 Calculate the output value (\( y \)) if the input value (\( x \)) is \( 2 \). (2)
- 3.1.2 Calculate the input value (\( x \)) if the output value (\( y \)) is \( 11 \). (2)
3.2 The volume of water \( V \) (in litres) in a \( 500\text{-litre} \) tank is recorded over a period of \( 50\text{ minutes} \).
• The tank starts completely empty.
• Water is pumped in at a steady, constant rate until the tank contains \( 300\text{ litres} \) exactly \( 20\text{ minutes} \) later.
• The water level then remains constant for \( 10\text{ minutes} \).
• Finally, a valve is opened, and the water is drained at a constant rate until the tank is completely empty \( 20\text{ minutes} \) later.
Based on the scenario above, answer the following questions:
- 3.2.1 How much water is in the tank at the very start (\( 0\text{ minutes} \))? (1)
- 3.2.2 During which specific time interval is the volume of water in the tank constant? (2)
- 3.2.3 If you were to draw this graph, would the data be considered discrete or continuous? Explain your answer briefly. (2)
- 3.2.4 Calculate the rate at which the water is pumped into the tank during the first \( 20\text{ minutes} \) (in litres per minute). (2)
3.3 Consider the Cartesian plane:
- 3.3.1 Write down the coordinates of point \( A \) if it starts at the origin, translates \( 3 \) units to the right, and then \( 5 \) units down. (2)
- 3.3.2 In which quadrant does the point \( B(-2 ; 6) \) lie? (1)
- 3.3.3 State whether the point \( C(0 ; 4) \) lies on the \( x \)-axis or the \( y \)-axis. (1)
- 3.3.4 If point \( D \) is currently at \( (4 ; -1) \) and it translates \( 2 \) units to the left, what are its new coordinates? (2)
MATHWISE ACADEMY
Grade 8 Mathematics: Test 1 • Data Handling: Probability
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Leave all probability answers as fractions in their simplest form unless specified otherwise.
- Write neatly and legibly.
QUESTION 1: PROBABILITY CONCEPTS AND THE SCALE [10]
1.1 Define the term "Sample Space" in the context of probability.
1.2 State whether the following statements are TRUE or FALSE:
- 1.2.1 The probability of any event always lies between \( 0 \) and \( 1 \) (inclusive). (1)
- 1.2.2 If an event has an even chance (50-50) of happening, its probability is \( 0,05 \). (1)
1.3 Assign a probability decimal (from \( 0 \) to \( 1 \)) to each of the following events:
- 1.3.1 The probability of a human being growing wings and flying tomorrow. (1)
- 1.3.2 The probability of tossing a fair coin and it landing on Heads. (1)
- 1.3.3 The probability of rolling a \( 7 \) on a standard 6-sided die. (1)
- 1.3.4 The probability of tomorrow being Tuesday if today is Monday. (1)
1.4 A jar contains \( 3 \) red marbles and \( 3 \) blue marbles.
- 1.4.1 What is the probability of picking a red marble? Write your answer as a fraction, a decimal, and a percentage. (3)
QUESTION 2: THEORETICAL PROBABILITY [18]
2.1 A standard 6-sided die is rolled. Determine the probability of rolling:
- 2.1.1 the number \( 4 \). (1)
- 2.1.2 an odd number. (2)
- 2.1.3 a prime number. (2)
- 2.1.4 a natural number less than \( 7 \). (1)
2.2 A card is drawn at random from a standard pack of \( 52 \) playing cards (excluding jokers). Calculate the probability of drawing:
- 2.2.1 a club. (2)
- 2.2.2 the King of Hearts. (2)
- 2.2.3 any red card. (2)
2.3 A letter is chosen at random from the word \( \text{STATISTICS} \). Determine the probability of choosing:
- 2.3.1 the letter \( \text{S} \). (2)
- 2.3.2 a vowel. (2)
- 2.3.3 the letter \( \text{T} \) or the letter \( \text{I} \). (2)
QUESTION 3: BAGS AND PREDICTIONS [12]
3.1 A bag contains \( 5 \) red balls, \( 3 \) blue balls, and \( 4 \) yellow balls. One ball is drawn out of the bag at random.
- 3.1.1 What is the probability of drawing a blue ball? (2)
- 3.1.2 What is the probability of drawing a red OR a yellow ball? (2)
- 3.1.3 What is the probability of drawing a green ball? (1)
- 3.1.4 What is the probability of drawing a ball that is NOT red? (2)
3.2 A spinner is divided into \( 8 \) equal-sized sectors, numbered \( 1 \) to \( 8 \).
- 3.2.1 Determine the probability of the spinner landing on a multiple of \( 3 \). (2)
- 3.2.2 If the spinner is spun \( 400 \) times, predict how many times you would expect it to land on a multiple of \( 3 \). (3)
QUESTION 4: EMPIRICAL PROBABILITY (RELATIVE FREQUENCY) [10]
4.1 A student throws a standard 6-sided die \( 60 \) times to test if it is fair. The results are recorded in the table below:
| Number on die | \( 1 \) | \( 2 \) | \( 3 \) | \( 4 \) | \( 5 \) | \( 6 \) |
|---|---|---|---|---|---|---|
| Frequency (Throws) | \( 8 \) | \( 12 \) | \( 10 \) | \( 9 \) | \( 15 \) | \( 6 \) |
- 4.1.1 Calculate the relative frequency (empirical probability) of rolling a \( 5 \). (2)
- 4.1.2 What is the theoretical probability of rolling a \( 5 \)? (2)
- 4.1.3 Calculate the relative frequency of rolling an even number during this experiment. (3)
- 4.1.4 Explain briefly why the relative frequency calculated in 4.1.1 is not exactly equal to the theoretical probability in 4.1.2. (2)
- 4.1.5 What will likely happen to the relative frequency if the student rolls the die \( 6\,000 \) times instead of \( 60 \) times? (1)
MATHWISE ACADEMY
Grade 8 Mathematics: Test 2 • Data Handling: Probability
Time: 1 Hour
Total Marks: 50
INSTRUCTIONS AND INFORMATION
- Answer ALL the questions.
- Read all questions carefully before you begin.
- Show ALL working out where applicable. Full marks will not necessarily be awarded for answers only.
- Leave all probability answers as fractions in their simplest form unless specified otherwise.
- Write neatly and legibly.
QUESTION 1: PROBABILITY CONCEPTS AND THE SCALE [10]
1.1 Define the term "Event" in the context of probability.
1.2 Assign a probability decimal (from \( 0 \) to \( 1 \)) to each of the following events:
- 1.2.1 The probability of rolling an \( 8 \) on a standard 6-sided die. (1)
- 1.2.2 The probability of tossing a fair coin and it landing on Tails. (1)
- 1.2.3 The probability of drawing a red ball from a bag containing exactly \( 10 \) red balls. (1)
- 1.2.4 The probability of the sun rising in the West tomorrow morning. (1)
1.3 State whether the following statements are TRUE or FALSE. If false, briefly correct the statement:
- 1.3.1 The probability of an event can be calculated to be \( 1,5 \). (2)
- 1.3.2 If you toss a single fair coin once, the sample space is \( \{\text{Heads}, \text{Tails}\} \). (2)
1.4 What is the total sum of the probabilities of all possible equally likely outcomes in a sample space?
QUESTION 2: THEORETICAL PROBABILITY [16]
2.1 A cash bag contains \( 20 \) five-rand coins, \( 30 \) two-rand coins, and \( 10 \) one-rand coins. Find the probability that one coin selected at random from the bag is:
- 2.1.1 a one-rand coin. (2)
- 2.1.2 a two-rand coin. (2)
- 2.1.3 a one-rand OR a five-rand coin. (2)
2.2 A letter is chosen at random from the word \( \text{REPRESENTATIVE} \). Determine the probability of choosing:
- 2.2.1 the letter \( \text{E} \). (2)
- 2.2.2 a vowel. (2)
2.3 A card is drawn at random from a standard pack of \( 52 \) playing cards (excluding jokers). Calculate the probability of drawing:
- 2.3.1 any black card. (2)
- 2.3.2 the Queen of Spades. (2)
- 2.3.3 a "face card" (i.e. a Jack, Queen, or King of any suit). (2)
QUESTION 3: NUMBERED BALLS AND PREDICTIONS [12]
3.1 Ten numbered balls (numbered \( 1 \) to \( 10 \)) are placed in a bag. One ball is taken out of the bag at random. Determine the probability of selecting a ball:
- 3.1.1 numbered \( 7 \). (1)
- 3.1.2 with an even number. (2)
- 3.1.3 with a prime number. (2)
- 3.1.4 with a number greater than \( 10 \). (1)
3.2 Probabilities can be used to make predictions:
- 3.2.1 A standard 6-sided die is rolled \( 1\,200 \) times. Predict how many times you would expect to roll a multiple of \( 3 \). (3)
- 3.2.2 The same die is rolled \( 600 \) times. Predict how many times you would expect to roll the number \( 4 \). (3)
QUESTION 4: EMPIRICAL PROBABILITY AND HIGH-ORDER CHALLENGE [12]
4.1 A survey of \( 80 \) people was conducted to find out their favourite flavour of frozen yoghurt. The results are as follows: Chocolate (\( 25 \) people), Vanilla (\( 15 \) people), Strawberry (\( 30 \) people), and Mint (\( 10 \) people).
- 4.1.1 Calculate the relative frequency (empirical probability) of a person choosing Strawberry. (2)
- 4.1.2 Calculate the relative frequency of a person choosing Mint OR Vanilla. (2)
- 4.1.3 If \( 400 \) people are surveyed at a similar event, predict how many people will choose Chocolate as their favourite flavour. (3)
4.2 Algebraic Probability Challenge:
One ball is selected at random from a bag containing \( 12 \) balls. Suppose that there are \( x \) red balls in the bag.
You add a further \( 6 \) red balls to the bag. The probability of now selecting a red ball is doubled.
Set up an equation and determine the original number of red balls (\( x \)).