Sri Lanka · Grade 8 · Practice Sheet 39

1. 1.

   Find the circumference of a circle whose radius is 11 m. (Use π ≈ 3.14159)

   Formula:Circumference of a Circle

   $C = 2\pi r$

   View formula →
2. 2.

   A triangle has a base of 22 cm and a height of 13 cm. Find its area.

   Formula:Area of a Triangle

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

   View formula →
3. 3.

   An object has mass 162.4 g and volume 29 cm³. Find its density.

   Formula:Density

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

   View formula →
4. 4.

   A circle has a radius of 13 cm. Find its area. (Use π ≈ 3.14159)

   Formula:Area of a Circle

   $A = \pi r^2$

   View formula →
5. 5.

   A force of 384 N acts on an area of 1.2 m². Find the pressure.

   Formula:Pressure

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

   View formula →
6. 6.

   A bag has 26 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 →
7. 7.

   Solve for x: 9x + 15 = 114.

   Formula:Solving a Linear Equation

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

   View formula →
8. 8.

   A force of 314 N acts on an area of 7.9 m². Find the pressure.

   Formula:Pressure

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

   View formula →
9. 9.

   A triangle has a base of 27 cm and a height of 30 cm. Find its area.

   Formula:Area of a Triangle

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

   View formula →
10. 10.

    Rs 800 is invested at 5% simple interest per year for 6 years. Find the interest earned.

    Formula:Simple Interest

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

    View formula →
11. 11.

    Solve for x: 8x + 16 = 72.

    Formula:Solving a Linear Equation

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

    View formula →
12. 12.

    A cylinder has radius 7 cm and height 18 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cylinder

    $V = \pi r^2 h$

    View formula →
13. 13.

    A bag has 21 equally likely marbles, of which 4 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 →
14. 14.

    Rs 48 is shared in the ratio 3 : 3. Find each share.

    Formula:Dividing in a Ratio

    $\text{share} = \dfrac{\text{part}}{\text{total parts}} \times T$

    View formula →
15. 15.

    A triangle has a base of 8 cm and a height of 3 cm. Find its area.

    Formula:Area of a Triangle

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

    View formula →
16. 16.

    Solve for x: 4x + 11 = 39.

    Formula:Solving a Linear Equation

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

    View formula →
17. 17.

    An object has mass 48 g and volume 16 cm³. Find its density.

    Formula:Density

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

    View formula →
18. 18.

    A current of 1.1 A flows through a 50 Ω resistor. Find the voltage across it.

    Formula:Ohm's Law

    $V = I R$

    View formula →
19. 19.

    Find the mean (average) of these numbers: 63, 12, 71, 45, 94.

    Formula:Arithmetic Mean

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

    View formula →
20. 20.

    Rs 120 is shared in the ratio 5 : 3. Find each share.

    Formula:Dividing in a Ratio

    $\text{share} = \dfrac{\text{part}}{\text{total parts}} \times T$

    View formula →

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