Lebanon · Grade 8 · Practice Sheet 28

1. 1.

   An object has mass 107.5 g and volume 43 cm³. Find its density.

   Formula:Density

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

   View formula →
2. 2.

   Find the mean (average) of these numbers: 63, 61, 87, 29, 23.

   Formula:Arithmetic Mean

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

   View formula →
3. 3.

   A bag has 25 equally likely marbles, of which 8 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 →
4. 4.

   A car travels 100 km in 2 hours. Find its average speed.

   Formula:Speed

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

   View formula →
5. 5.

   A right-angled triangle has legs of 3 cm and 17 cm. Find the length of the hypotenuse.

   Formula:Pythagorean Theorem

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

   View formula →
6. 6.

   A current of 0.7 A flows through a 45 Ω resistor. Find the voltage across it.

   Formula:Ohm's Law

   $V = I R$

   View formula →
7. 7.

   A train moves at 47 km/h for 3.1 hours. How far does it travel?

   Formula:Distance from Speed & Time

   $d = v \times t$

   View formula →
8. 8.

   Solve for x: 2x + 9 = 21.

   Formula:Solving a Linear Equation

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

   View formula →
9. 9.

   What is 10% of 220?

   Formula:Percentage of a Quantity

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

   View formula →
10. 10.

    A current of 0.5 A flows through a 4 Ω resistor. Find the voltage across it.

    Formula:Ohm's Law

    $V = I R$

    View formula →
11. 11.

    An object has mass 30 g and volume 6 cm³. Find its density.

    Formula:Density

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

    View formula →
12. 12.

    A current of 0.5 A flows through a 51 Ω resistor. Find the voltage across it.

    Formula:Ohm's Law

    $V = I R$

    View formula →
13. 13.

    An object has mass 243.6 g and volume 42 cm³. Find its density.

    Formula:Density

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

    View formula →
14. 14.

    What is 25% of 120?

    Formula:Percentage of a Quantity

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

    View formula →
15. 15.

    A right-angled triangle has legs of 12 cm and 3 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

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

    View formula →
16. 16.

    LL 2,900 is invested at 5% simple interest per year for 5 years. Find the interest earned.

    Formula:Simple Interest

    $I = \dfrac{P \times r \times t}{100}$

    View formula →
17. 17.

    A cylinder has radius 2 cm and height 28 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cylinder

    $V = \pi r^2 h$

    View formula →
18. 18.

    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 →
19. 19.

    A car travels 255 km in 3 hours. Find its average speed.

    Formula:Speed

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

    View formula →
20. 20.

    Find the mean (average) of these numbers: 99, 47, 11, 76, 46, 53.

    Formula:Arithmetic Mean

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

    View formula →

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