Taiwan · Grade 8 · Practice Sheet 47

1. 1.

   Solve for x: 6x + 12 = 84.

   Formula:Solving a Linear Equation

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

   View formula →
2. 2.

   A current of 6.4 A flows through a 42 Ω resistor. Find the voltage across it.

   Formula:Ohm's Law

   $V = I R$

   View formula →
3. 3.

   A force of 404 N acts on an area of 3.3 m². Find the pressure.

   Formula:Pressure

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

   View formula →
4. 4.

   A value changes from 92 to 216. 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.

   Find the circumference of a circle whose radius is 25 m. (Use π ≈ 3.14159)

   Formula:Circumference of a Circle

   $C = 2\pi r$

   View formula →
6. 6.

   Find the mean (average) of these numbers: 14, 96, 30, 27, 41.

   Formula:Arithmetic Mean

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

   View formula →
7. 7.

   A current of 3.8 A flows through a 54 Ω resistor. Find the voltage across it.

   Formula:Ohm's Law

   $V = I R$

   View formula →
8. 8.

   A car travels 126 km in 3 hours. Find its average speed.

   Formula:Speed

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

   View formula →
9. 9.

   Find the circumference of a circle whose radius is 14 m. (Use π ≈ 3.14159)

   Formula:Circumference of a Circle

   $C = 2\pi r$

   View formula →
10. 10.

    What is 10% of 180?

    Formula:Percentage of a Quantity

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

    View formula →
11. 11.

    An object has mass 31.5 g and volume 35 cm³. Find its density.

    Formula:Density

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

    View formula →
12. 12.

    A current of 2.7 A flows through a 56 Ω resistor. Find the voltage across it.

    Formula:Ohm's Law

    $V = I R$

    View formula →
13. 13.

    Solve for x: 6x + 20 = 62.

    Formula:Solving a Linear Equation

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

    View formula →
14. 14.

    A bag has 20 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 →
15. 15.

    A right-angled triangle has legs of 6 cm and 11 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

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

    View formula →
16. 16.

    NT$ 4,800 is invested at 3% 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.

    An object has mass 164 g and volume 20 cm³. Find its density.

    Formula:Density

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

    View formula →
18. 18.

    A circle has a radius of 4 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

    View formula →
19. 19.

    Find the circumference of a circle whose radius is 27 m. (Use π ≈ 3.14159)

    Formula:Circumference of a Circle

    $C = 2\pi r$

    View formula →
20. 20.

    Find the mean (average) of these numbers: 31, 90, 57, 13.

    Formula:Arithmetic Mean

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

    View formula →

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