A boy was asked to multiply a number of 3/5 but the divided the number by 3/5. Hence he got 160 more than correct answer. Find the number.

Let the given number x

According to the condition  $x\times \frac{3}{5}=\frac{3x}{5}$

But by mistake a student divides the given number  $x÷\frac{3}{5}=\frac{5x}{3}$

Hence   $\frac{5x}{3}-\frac{3x}{5}=160$

$\frac{25x-9x}{15}=160$

$16x=160\times 15$

$x=150$