Ecuador · Grado 7 · Practice Sheet 25

1. 1.

   A value changes from 39 to 161. 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.

   Find the perimeter of a rectangle measuring 45 m by 16 m.

   Formula:Perimeter of a Rectangle

   $P = 2(l + w)$

   View formula →
3. 3.

   $84 is shared in the ratio 1 : 2. Find each share.

   Formula:Dividing in a Ratio

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

   View formula →
4. 4.

   Find the mean (average) of these numbers: 72, 74, 51, 21, 93.

   Formula:Arithmetic Mean

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

   View formula →
5. 5.

   A bag has 28 equally likely marbles, of which 1 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 →
6. 6.

   Convert 8.71 kilometres into metres.

   Formula:Metric Length Conversion

   $1\,\text{km} = 1000\,\text{m}$

   View formula →
7. 7.

   A right-angled triangle has legs of 11 cm and 12 cm. Find the length of the hypotenuse.

   Formula:Pythagorean Theorem

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

   View formula →
8. 8.

   A car travels 462 km in 6 hours. Find its average speed.

   Formula:Speed

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

   View formula →
9. 9.

   Find the area of a square with side length 19 cm.

   Formula:Area of a Square

   $A = s^2$

   View formula →
10. 10.

    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 →
11. 11.

    Find 2/3 of 45.

    Formula:Fraction of a Quantity

    $\text{result} = \dfrac{a}{b} \times N$

    View formula →
12. 12.

    $95 is shared in the ratio 2 : 3. Find each share.

    Formula:Dividing in a Ratio

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

    View formula →
13. 13.

    A right-angled triangle has legs of 8 cm and 17 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

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

    View formula →
14. 14.

    What is 25% of 140?

    Formula:Percentage of a Quantity

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

    View formula →
15. 15.

    Solve for x: 2x + 6 = 16.

    Formula:Solving a Linear Equation

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

    View formula →
16. 16.

    Find the area of a square with side length 28 cm.

    Formula:Area of a Square

    $A = s^2$

    View formula →
17. 17.

    Solve for x: 2x + 5 = 9.

    Formula:Solving a Linear Equation

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

    View formula →
18. 18.

    A circle has a radius of 22 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

    View formula →
19. 19.

    $1,400 is invested at 5% simple interest per year for 3 years. Find the interest earned.

    Formula:Simple Interest

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

    View formula →
20. 20.

    What is 12% of 450?

    Formula:Percentage of a Quantity

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

    View formula →

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