Topic – C1.1
Write the number two million eight hundred and forty thousand three hundred and twenty-seven in figures.
▶️ Answer/Explanation
Ans: 2,840,327
Break it down: two million (2,000,000) + eight hundred forty thousand (840,000) + three hundred (300) + twenty-seven (27) = 2,840,327.
Topic – C4.6
Write down the mathematical name of this type of angle.
▶️ Answer/Explanation
Ans: Obtuse
An obtuse angle is any angle greater than 90° but less than 180°. The diagram shows an angle in this range.
Topic – C4.2
Draw a line perpendicular to this line.
▶️ Answer/Explanation
Ans: A perpendicular line forms a 90° angle with the original line. Use a protractor or right angle tool to draw it accurately.
Topic – C4.2
In triangle PQR, PR = 5 cm and QR = 4 cm.
Using a ruler and compasses only, construct triangle PQR.
Leave in your construction arcs.
The side PQ has been drawn for you.
▶️ Answer/Explanation
Ans: [Correct triangle constructed]
1. From point P, draw an arc with radius 5 cm. From point Q, draw an arc with radius 4 cm.
2. The intersection point of these arcs is point R. Connect P to R and Q to R to complete the triangle.
Topic – C1.1
Write down a common multiple of 18 and 24.
▶️ Answer/Explanation
Ans: 72 (or any multiple of 72)
The LCM of 18 (2×3²) and 24 (2³×3) is 2³×3² = 72. Any multiple of 72 (e.g., 72, 144, 216) is a correct answer.
Topic – C1.11
Write 32 cm as a fraction of 2 m.
Give your answer in its simplest form.
▶️ Answer/Explanation
Ans: 4/25
First convert 2m to cm: 2m = 200cm. The fraction is 32/200. Simplify by dividing numerator and denominator by 8: 32÷8=4, 200÷8=25.
Topic – C1.5
The temperature, in °C, is recorded at the same time in six cities.
London | Helsinki | Oslo | Paris | Madrid | Berlin |
6 | -2 | -5 | 7 | 9 | 2 |
(a) Which city has the coldest temperature?
(b) What is the difference in temperature between Helsinki and Paris?
▶️ Answer/Explanation
Ans: (a) Oslo (b) 9°C
(a) The coldest temperature is -5°C in Oslo.
(b) Difference = Paris (7°C) – Helsinki (-2°C) = 7 – (-2) = 9°C.
Topic – C4.6
The diagram shows two straight lines intersecting two parallel lines. Find the value of x.
▶️ Answer/Explanation
Ans: 54
Angles in a triangle add up to 180°. Given two angles are 71° and 55°, so x = 180 – 71 – 55 = 54°.
Topic – C1.11
Divide $200 in the ratio 7:3.
▶️ Answer/Explanation
Ans: $140, $60
Total parts = 7 + 3 = 10. Value per part = $200 ÷ 10 = $20. First share = 7 × $20 = $140, second share = 3 × $20 = $60.
Topic – C9.4
The birth weights, in kg, of 11 babies are recorded:
2.1 1.6 2.7 4.2 4.0 2.2 3.1 1.7 2.6 3.3 3.7
(a) Complete the stem-and-leaf diagram to show this information.
(b) Find the median.
▶️ Answer/Explanation
Ans: (a) Stem-and-leaf completed (b) 2.7 kg
(a) Stem-and-leaf:
(b) Ordered data: 1.6,1.7,2.1,2.2,2.6,2.7,3.1,3.3,3.7,4.0,4.2. Median is the 6th value = 2.7 kg.
Topic – C9.4
Victoria records the colour of each of 240 cars leaving a car park. Some of this information is shown in the pie chart.
(a) Show that 60 cars are blue.
(b) The rest of the cars are either red or white.
110 cars are red.
Complete the pie chart to show this information.
▶️ Answer/Explanation
(a) The blue sector is 90° out of 360°, so fraction is 90/360 = 1/4. 1/4 of 240 cars = 60 cars.
(b) Total remaining cars = 240 – 60 – 110 = 70 white cars. Red sector angle = (110/240)×360 = 165°, white sector angle = (70/240)×360 = 105°.
Topic – C1.13
The price of a computer is $520.
This price is reduced by 15% in a sale.
Work out the sale price.
▶️ Answer/Explanation
Original price = $520
15% reduction = 0.15 × 520 = $78
Sale price = 520 – 78 = $442
Topic – C1.4
Without using a calculator, work out \(\frac{1}{3} + \frac{5}{6}\).
You must show all your working and give your answer as a mixed number in its simplest form.
▶️ Answer/Explanation
Find common denominator (6):
\(\frac{1}{3} = \frac{2}{6}\)
\(\frac{2}{6} + \frac{5}{6} = \frac{7}{6}\)
Convert to mixed number: \(1\frac{1}{6}\)
Topic – C8.1
Mario tests new cars. The probability that a car is faulty is 0.04.
(a) Find the probability that a car is not faulty.
(b) In one week Mario tests 850 cars. Find the number of cars that are expected to be faulty.
▶️ Answer/Explanation
(a) P(not faulty) = 1 – P(faulty) = 1 – 0.04 = 0.96
(b) Expected faulty cars = 850 × 0.04 = 34 cars
Topic – C1.4
A café sells 330 sandwiches.
This is \(\frac{11}{14}\) of the sandwiches they make.
Work out the number of sandwiches the café makes.
▶️ Answer/Explanation
Let total sandwiches be x
\(\frac{11}{14}x = 330\)
\(x = 330 × \frac{14}{11}\)
\(x = 420\) sandwiches
Topic – C2.10
(a) Complete the table of values for \( y = \frac{5}{x}\)
x | -5 | -4 | -2.5 | -2 | -1 | 1 | 2 | 2.5 | 4 | 5 |
y | -1 | -2 | -2.5 | -5 | 5 | 2.5 | 2 | 1 |
(b) On the grid, draw the graph of \( y = \frac{5}{x}\) for -5 ≤ x ≤ -1 and 1 ≤ x ≤ 5.
▶️ Answer/Explanation
(a) Missing values: -1.25 (x=-4), 1.25 (x=4)
Calculated by y = 5/x: 5/-4 = -1.25 and 5/4 = 1.25
(b) Hyperbola graph
Plot all points from the table and draw two smooth curves (one in negative x, one in positive x) approaching but never touching the axes.
Topic – C2.7
(a) 3, 9, 27, 81, …
Write down the term to term rule for this sequence.
(b) 13, 17, 21, 25, …
Find the nth term of this sequence.
▶️ Answer/Explanation
(a) ×3
Each term is multiplied by 3 to get the next term.
(b) 4n + 9
The common difference is 4, and the first term minus the difference gives 9 when n=1.
Topic – C1.2
The Venn diagram shows elements of sets ξ, P and Q. Complete the statements.
(a) Write down the elements of set P.
(b) Find n(P ∪ Q).
▶️ Answer/Explanation
(a) {a, b, c, d}
These are the elements shown inside circle P.
(b) 6
Counting all elements in P or Q gives 6 elements.
Topic – C4.6
The bearing of A from B is 137°. Find the bearing of B from A.
▶️ Answer/Explanation
317°
To find the reverse bearing, add 180° to 137°.
137° + 180° = 317°.
Topic – C1.8
(a) Write 0.00273 in standard form.
(b) Sam has to answer this question.
Sam writes \( 42.1 \times 10^{6}\) as his answer to this question.
What two errors has Sam made?
▶️ Answer/Explanation
(a) 2.73 × 10⁻³
Move decimal 3 places right for standard form.
(b) 1) 42.1 is incorrectly rounded [to 3 significant figures]
2) \( 42.1 \times 10^{6}\) is not correct standard form
Topic – C4.4
Triangle ABC is mathematically similar to triangle DEF.
Find BC.
▶️ Answer/Explanation
Ans: 34 cm
Since triangles are similar, corresponding sides are proportional.
Scale factor = AB/DE = 51/6 = 8.5
Therefore, BC = EF × scale factor = 4 × 8.5 = 34 cm
Topic – C6.2
The diagram shows a right-angled triangle.
Show that the value of x is 15.8, correct to 3 significant figures.
▶️ Answer/Explanation
Ans: 15.8 cm
Using tangent function: tan(48°) = opposite/adjacent = x/17.5
Therefore, x = 17.5 × tan(48°) ≈ 17.5 × 1.1106 ≈ 19.435
Alternatively, tan(42°) = 17.5/x → x ≈ 17.5/0.9004 ≈ 19.435
Rounding to 3 significant figures gives x ≈ 19.4 cm
Topic – C2.5
Natalie buys 4 tomato plants and 3 pepper plants for $9.35 .
Samir buys 2 tomato plants and 11 pepper plants for $16.55 .
Write down a pair of simultaneous equations and solve them to find the cost of one tomato plant and the cost of one pepper plant.
You must show all your working.
▶️ Answer/Explanation
Ans: Tomato plant $1.41, Pepper plant $1.25
Let t = tomato plant price, p = pepper plant price.
Equation 1: 4t + 3p = 9.35
Equation 2: 2t + 11p = 16.55
Multiply Equation 2 by 2: 4t + 22p = 33.10
Subtract Equation 1: 19p = 23.75 → p = 1.25
Substitute p into Equation 1: 4t + 3.75 = 9.35 → t = 1.40