Chile · Grado 8 · Practice Sheet 31

1. 1.

   A value changes from 187 to 257. Find the percentage change (to 2 d.p.).

   Formula:Percentage Change

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

   View formula →
2. 2.

   A right-angled triangle has legs of 16 cm and 14 cm. Find the length of the hypotenuse.

   Formula:Pythagorean Theorem

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

   View formula →
3. 3.

   Find the mean (average) of these numbers: 12, 95, 56, 76.

   Formula:Arithmetic Mean

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

   View formula →
4. 4.

   A triangle has a base of 37 cm and a height of 8 cm. Find its area.

   Formula:Area of a Triangle

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

   View formula →
5. 5.

   A force of 266 N acts on an area of 5.8 m². Find the pressure.

   Formula:Pressure

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

   View formula →
6. 6.

   A triangle has a base of 19 cm and a height of 18 cm. Find its area.

   Formula:Area of a Triangle

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

   View formula →
7. 7.

   What is 5% of 260?

   Formula:Percentage of a Quantity

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

   View formula →
8. 8.

   Find the mean (average) of these numbers: 94, 47, 32, 51, 75, 47.

   Formula:Arithmetic Mean

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

   View formula →
9. 9.

   What is 10% of 490?

   Formula:Percentage of a Quantity

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

   View formula →
10. 10.

    A train moves at 46 km/h for 2.5 hours. How far does it travel?

    Formula:Distance from Speed & Time

    $d = v \times t$

    View formula →
11. 11.

    Find the circumference of a circle whose radius is 28 m. (Use π ≈ 3.14159)

    Formula:Circumference of a Circle

    $C = 2\pi r$

    View formula →
12. 12.

    Solve for x: 5x + 13 = 23.

    Formula:Solving a Linear Equation

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

    View formula →
13. 13.

    A force of 308 N acts on an area of 5.5 m². Find the pressure.

    Formula:Pressure

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

    View formula →
14. 14.

    Solve for x: 8x + 11 = 27.

    Formula:Solving a Linear Equation

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

    View formula →
15. 15.

    A circle has a radius of 23 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

    View formula →
16. 16.

    A car travels 428 km in 4 hours. Find its average speed.

    Formula:Speed

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

    View formula →
17. 17.

    Find the circumference of a circle whose radius is 23 m. (Use π ≈ 3.14159)

    Formula:Circumference of a Circle

    $C = 2\pi r$

    View formula →
18. 18.

    $900 is invested at 8% simple interest per year for 5 years. Find the interest earned.

    Formula:Simple Interest

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

    View formula →
19. 19.

    A cylinder has radius 4 cm and height 30 cm. Find its volume. (π ≈ 3.14159)

    Formula:Volume of a Cylinder

    $V = \pi r^2 h$

    View formula →
20. 20.

    $108 is shared in the ratio 4 : 2. 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.