Question

If two – thirds of five – seventh of a number is $100$. Find the number.

Answer 1

Let the number be $x,$
Then, $\frac{2}{3}\text{of}\frac{5}{7}\text{of}x=100$
$\Rightarrow \frac{2}{3}\times (\frac{5}{7}\times x)=100$
$\Rightarrow \frac{2}{3}\times \frac{5x}{7}=100$
$\Rightarrow \frac{10x}{21}=100$
$\Rightarrow 10x=100\times 21$
$\to x=2100÷10$
$\Rightarrow x=210$
The required number $=210$