Question

A boy was asked to multiply a given number by $\frac{8}{17}.$ Instead, he divided the given number by $\frac{8}{17}$ and got the result $225$ more than what he should have got if he had multiplied the number by $\frac{8}{17}.$ The given number was

• A. $8$
• B. $17$
• C. $64$
• D. $136$

Answer 1

The correct option is D $136$

Let the number be $x$

Result when calculated wrongly $=\frac{17x}{8}...\left(I\right)$

Result when calculated correctly $=\frac{8x}{17}...\left(II\right)$

$\left(I\right)-\left(II\right)=225$

$\Rightarrow \frac{17x}{8}-\frac{8x}{17}=225$

$\Rightarrow \frac{289-64}{136}x=225$

$\Rightarrow \frac{225}{136}x=225$

$\Rightarrow x=136$