South Africa · Grade 8 · Practice Sheet 43

1. 1.

   A car travels 525 km in 5 hours. Find its average speed.

   Formula:Speed

   $v = \dfrac{d}{t}$

   View formula →
2. 2.

   A bag has 23 equally likely marbles, of which 21 are red. Find the probability of drawing a red marble (to 3 d.p.).

   Formula:Simple Probability

   $P(E) = \dfrac{\text{favourable}}{\text{total}}$

   View formula →
3. 3.

   Solve for x: 2x + 9 = 31.

   Formula:Solving a Linear Equation

   $x = \dfrac{c - b}{a}$

   View formula →
4. 4.

   A car travels 420 km in 5 hours. Find its average speed.

   Formula:Speed

   $v = \dfrac{d}{t}$

   View formula →
5. 5.

   Find the mean (average) of these numbers: 49, 90, 91, 77.

   Formula:Arithmetic Mean

   $\bar{x} = \dfrac{\sum x}{n}$

   View formula →
6. 6.

   A bag has 28 equally likely marbles, of which 23 are red. Find the probability of drawing a red marble (to 3 d.p.).

   Formula:Simple Probability

   $P(E) = \dfrac{\text{favourable}}{\text{total}}$

   View formula →
7. 7.

   What is 50% of 330?

   Formula:Percentage of a Quantity

   $\text{result} = \dfrac{p}{100} \times N$

   View formula →
8. 8.

   A train moves at 87 km/h for 2.5 hours. How far does it travel?

   Formula:Distance from Speed & Time

   $d = v \times t$

   View formula →
9. 9.

   Find the circumference of a circle whose radius is 20 m. (Use π ≈ 3.14159)

   Formula:Circumference of a Circle

   $C = 2\pi r$

   View formula →
10. 10.

    Find the mean (average) of these numbers: 82, 13, 58, 51, 76, 23.

    Formula:Arithmetic Mean

    $\bar{x} = \dfrac{\sum x}{n}$

    View formula →
11. 11.

    A force of 480 N acts on an area of 0.7 m². Find the pressure.

    Formula:Pressure

    $P = \dfrac{F}{A}$

    View formula →
12. 12.

    A bag has 24 equally likely marbles, of which 7 are red. Find the probability of drawing a red marble (to 3 d.p.).

    Formula:Simple Probability

    $P(E) = \dfrac{\text{favourable}}{\text{total}}$

    View formula →
13. 13.

    An object has mass 107.2 g and volume 16 cm³. Find its density.

    Formula:Density

    $\rho = \dfrac{m}{V}$

    View formula →
14. 14.

    A circle has a radius of 25 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

    View formula →
15. 15.

    Find the mean (average) of these numbers: 11, 57, 79, 44, 63.

    Formula:Arithmetic Mean

    $\bar{x} = \dfrac{\sum x}{n}$

    View formula →
16. 16.

    A cylinder has radius 11 cm and height 23 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cylinder

    $V = \pi r^2 h$

    View formula →
17. 17.

    A value changes from 129 to 66. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

    $\%\,\text{change} = \dfrac{\text{new} - \text{old}}{\text{old}} \times 100$

    View formula →
18. 18.

    A circle has a radius of 12 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

    View formula →
19. 19.

    A train moves at 61 km/h for 3.3 hours. How far does it travel?

    Formula:Distance from Speed & Time

    $d = v \times t$

    View formula →
20. 20.

    A force of 321 N acts on an area of 2.6 m². Find the pressure.

    Formula:Pressure

    $P = \dfrac{F}{A}$

    View formula →

© FormulaWon — formulawon.app · Answers & step-by-step working available on the solutions sheet.