South Korea · Grade 7 · Practice Sheet 5

1. 1.

   Find the mean (average) of these numbers: 33, 61, 48, 69.

   Formula:Arithmetic Mean

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

   View formula →
2. 2.

   Find the area of a square with side length 11 cm.

   Formula:Area of a Square

   $A = s^2$

   View formula →
3. 3.

   A value changes from 145 to 55. Find the percentage change (to 2 d.p.).

   Formula:Percentage Change

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

   View formula →
4. 4.

   Find the area of a square with side length 13 cm.

   Formula:Area of a Square

   $A = s^2$

   View formula →
5. 5.

   A rectangle is 30 cm long and 9 cm wide. Find its area.

   Formula:Area of a Rectangle

   $A = l \times w$

   View formula →
6. 6.

   Find the area of a square with side length 11 cm.

   Formula:Area of a Square

   $A = s^2$

   View formula →
7. 7.

   ₩2,000 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 →
8. 8.

   Convert 2.69 kilometres into metres.

   Formula:Metric Length Conversion

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

   View formula →
9. 9.

   A car travels 528 km in 8 hours. Find its average speed.

   Formula:Speed

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

   View formula →
10. 10.

    Find the mean (average) of these numbers: 31, 83, 79, 52, 69.

    Formula:Arithmetic Mean

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

    View formula →
11. 11.

    A value changes from 118 to 149. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

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

    View formula →
12. 12.

    A rectangle is 11 cm long and 19 cm wide. Find its area.

    Formula:Area of a Rectangle

    $A = l \times w$

    View formula →
13. 13.

    ₩3,900 is invested at 10% simple interest per year for 2 years. Find the interest earned.

    Formula:Simple Interest

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

    View formula →
14. 14.

    Find the perimeter of a rectangle measuring 17 m by 33 m.

    Formula:Perimeter of a Rectangle

    $P = 2(l + w)$

    View formula →
15. 15.

    A car travels 202 km in 2 hours. Find its average speed.

    Formula:Speed

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

    View formula →
16. 16.

    Find the perimeter of a rectangle measuring 45 m by 32 m.

    Formula:Perimeter of a Rectangle

    $P = 2(l + w)$

    View formula →
17. 17.

    Convert 1.31 kilometres into metres.

    Formula:Metric Length Conversion

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

    View formula →
18. 18.

    ₩900 is invested at 8% simple interest per year for 4 years. Find the interest earned.

    Formula:Simple Interest

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

    View formula →
19. 19.

    A bag has 14 equally likely marbles, of which 13 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 →
20. 20.

    A right-angled triangle has legs of 19 cm and 5 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

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

    View formula →

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