Question

7. Find the value of:
a) The number when 40% of the number is 10

Answer 1

Step 1) Set up a proportion

Proportion: percent / 100 = x / number

In context of the problem, the proportion is: 40 / 100 = 10 / number

Step 2) Cross-multiply and solve

100 x 10 = 40 x N

1000 = 40N

N = 25

Answer: The number is 25

Answer 2

Answer:

25

Step-by-step explanation:

Let the unknown number be x

$40 \% \times x = 10 \\ \frac{40x}{100} = \frac{10}{1}$

Cross Multiply

$40x = 100 \times 10 \\ 40x = 1000$

Divide both sides of the equation by 40

$\frac{40x}{40} = \frac{1000}{40}$

Simplify

$x = 25$