Sri Lanka · Grade 8 · Practice Sheet 22

1. 1.

   Solve for x: 8x + 18 = 114.

   Formula:Solving a Linear Equation

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

   View formula →
2. 2.

   Find the circumference of a circle whose radius is 8 m. (Use π ≈ 3.14159)

   Formula:Circumference of a Circle

   $C = 2\pi r$

   View formula →
3. 3.

   A right-angled triangle has legs of 16 cm and 18 cm. Find the length of the hypotenuse.

   Formula:Pythagorean Theorem

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

   View formula →
4. 4.

   A bag has 29 equally likely marbles, of which 10 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 →
5. 5.

   Solve for x: 8x + 20 = 84.

   Formula:Solving a Linear Equation

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

   View formula →
6. 6.

   A car travels 700 km in 7 hours. Find its average speed.

   Formula:Speed

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

   View formula →
7. 7.

   A value changes from 186 to 101. Find the percentage change (to 2 d.p.).

   Formula:Percentage Change

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

   View formula →
8. 8.

   What is 50% of 460?

   Formula:Percentage of a Quantity

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

   View formula →
9. 9.

   A train moves at 49 km/h for 4.7 hours. How far does it travel?

   Formula:Distance from Speed & Time

   $d = v \times t$

   View formula →
10. 10.

    Find the circumference of a circle whose radius is 6 m. (Use π ≈ 3.14159)

    Formula:Circumference of a Circle

    $C = 2\pi r$

    View formula →
11. 11.

    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 →
12. 12.

    A circle has a radius of 20 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

    View formula →
13. 13.

    Rs 600 is invested at 4% simple interest per year for 3 years. Find the interest earned.

    Formula:Simple Interest

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

    View formula →
14. 14.

    What is 10% of 230?

    Formula:Percentage of a Quantity

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

    View formula →
15. 15.

    A circle has a radius of 18 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

    View formula →
16. 16.

    Find the mean (average) of these numbers: 70, 92, 55, 71, 46, 73.

    Formula:Arithmetic Mean

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

    View formula →
17. 17.

    A cylinder has radius 3 cm and height 14 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cylinder

    $V = \pi r^2 h$

    View formula →
18. 18.

    A force of 125 N acts on an area of 1.3 m². Find the pressure.

    Formula:Pressure

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

    View formula →
19. 19.

    A triangle has a base of 21 cm and a height of 5 cm. Find its area.

    Formula:Area of a Triangle

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

    View formula →
20. 20.

    A cylinder has radius 14 cm and height 5 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cylinder

    $V = \pi r^2 h$

    View formula →

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