Taiwan · Grade 8 · Practice Sheet 3

1. 1.

   A force of 145 N acts on an area of 3.3 m². Find the pressure.

   Formula:Pressure

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

   View formula →
2. 2.

   A current of 5 A flows through a 4 Ω resistor. Find the voltage across it.

   Formula:Ohm's Law

   $V = I R$

   View formula →
3. 3.

   A right-angled triangle has legs of 15 cm and 19 cm. Find the length of the hypotenuse.

   Formula:Pythagorean Theorem

   $c = \sqrt{a^2 + b^2}$

   View formula →
4. 4.

   A value changes from 36 to 129. Find the percentage change (to 2 d.p.).

   Formula:Percentage Change

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

   View formula →
5. 5.

   A car travels 178 km in 2 hours. Find its average speed.

   Formula:Speed

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

   View formula →
6. 6.

   Find the mean (average) of these numbers: 11, 10, 32, 38, 51.

   Formula:Arithmetic Mean

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

   View formula →
7. 7.

   A bag has 24 equally likely marbles, of which 5 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 →
8. 8.

   A value changes from 68 to 163. Find the percentage change (to 2 d.p.).

   Formula:Percentage Change

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

   View formula →
9. 9.

   A train moves at 30 km/h for 2.1 hours. How far does it travel?

   Formula:Distance from Speed & Time

   $d = v \times t$

   View formula →
10. 10.

    A right-angled triangle has legs of 6 cm and 5 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

    $c = \sqrt{a^2 + b^2}$

    View formula →
11. 11.

    Solve for x: 6x + 16 = 82.

    Formula:Solving a Linear Equation

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

    View formula →
12. 12.

    An object has mass 185.6 g and volume 29 cm³. Find its density.

    Formula:Density

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

    View formula →
13. 13.

    A right-angled triangle has legs of 17 cm and 9 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

    $c = \sqrt{a^2 + b^2}$

    View formula →
14. 14.

    A cylinder has radius 10 cm and height 12 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cylinder

    $V = \pi r^2 h$

    View formula →
15. 15.

    A triangle has a base of 18 cm and a height of 22 cm. Find its area.

    Formula:Area of a Triangle

    $A = \tfrac{1}{2} b h$

    View formula →
16. 16.

    A bag has 12 equally likely marbles, of which 6 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 →
17. 17.

    A value changes from 133 to 209. 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 bag has 8 equally likely marbles, of which 6 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 →
19. 19.

    Find the mean (average) of these numbers: 69, 57, 17, 10, 77.

    Formula:Arithmetic Mean

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

    View formula →
20. 20.

    A triangle has a base of 36 cm and a height of 30 cm. Find its area.

    Formula:Area of a Triangle

    $A = \tfrac{1}{2} b h$

    View formula →

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