United States · Grade 7 · Practice Sheet 38

1. 1.

   Find the mean (average) of these numbers: 63, 42, 28, 29, 78, 89.

   Formula:Arithmetic Mean

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

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2. 2.

   One item costs $24.73. Find the total cost of 16 items.

   Formula:Total Cost

   $\text{total} = \text{price} \times \text{quantity}$

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3. 3.

   What is 75% of 320?

   Formula:Percentage of a Quantity

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

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4. 4.

   Find the area of a square with side length 5 cm.

   Formula:Area of a Square

   $A = s^2$

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5. 5.

   What is 12% of 110?

   Formula:Percentage of a Quantity

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

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6. 6.

   Find the area of a square with side length 15 cm.

   Formula:Area of a Square

   $A = s^2$

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7. 7.

   A value changes from 60 to 74. Find the percentage change (to 2 d.p.).

   Formula:Percentage Change

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

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8. 8.

   Find 4/8 of 72.

   Formula:Fraction of a Quantity

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

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9. 9.

   A car travels 147 km in 3 hours. Find its average speed.

   Formula:Speed

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

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10. 10.

    A value changes from 38 to 37. Find the percentage change (to 2 d.p.).

    Formula:Percentage Change

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

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11. 11.

    Convert 11.54 kilometres into metres.

    Formula:Metric Length Conversion

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

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12. 12.

    What is 10% of 330?

    Formula:Percentage of a Quantity

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

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13. 13.

    A circle has a radius of 5 cm. Find its area. (Use π ≈ 3.14159)

    Formula:Area of a Circle

    $A = \pi r^2$

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14. 14.

    Find the mean (average) of these numbers: 35, 86, 28, 73.

    Formula:Arithmetic Mean

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

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15. 15.

    A bag has 22 equally likely marbles, of which 15 are red. Find the probability of drawing a red marble (to 3 d.p.).

    Formula:Simple Probability

    $P(E) = \dfrac{\text{favourable}}{\text{total}}$

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16. 16.

    Solve for x: 2x + 10 = 20.

    Formula:Solving a Linear Equation

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

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17. 17.

    A right-angled triangle has legs of 8 cm and 18 cm. Find the length of the hypotenuse.

    Formula:Pythagorean Theorem

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

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18. 18.

    Find the perimeter of a rectangle measuring 21 m by 22 m.

    Formula:Perimeter of a Rectangle

    $P = 2(l + w)$

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19. 19.

    Convert 5.92 kilometres into metres.

    Formula:Metric Length Conversion

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

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20. 20.

    Find 2/3 of 48.

    Formula:Fraction of a Quantity

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

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