Question

10% of what number is 3005% of what number is 72

Answer 1

1)

Given that 10 % of a number is 300.

Let x be the required number.

$10\text{\% of x is 300}$

$10\text{\% }\times x=\text{ 300}$

$\frac{10}{100}\times x=\text{ 300}$

$\frac{1}{10}\times x=\text{ 300}$

Multiplying 10 on both sides, we get

$\frac{1}{10}\times x\times10=300\times10$$x=3000$

Hence 10 % of 3000 is 300.

2)

Given that 5 % of a number is 72.

Let x be the required number.

$5\text{\% of x is 7}2$

$5\text{\% }\times x=\text{ 7}2$

$\frac{5}{100}\times x=72$

$\frac{1}{20}\times x=72$

Multiplying 20 on both sides, we get

$\frac{1}{20}\times x\times20=72\times20$$x=1440$

Hence 5% of 1440 is 72.