Question

The cost price of $16$ books is equal to the selling price of $12$ books. Find the gain percent.

Answer 1

Let the $CP$ of one book be $Rs.x$. So,

$CP$ of $16$ books $=Rs.16x$

According to the question,

$SP$ of $12$ books $=Rs.16x$

Therefore,

$SP$ of one book $=Rs.\frac{16x}{12}=Rs.\frac{4x}{3}$

Therefore,

$Gain\%=\frac{(\frac{4x}{3}-x)}{x}\times 100=\frac{x}{3x}\times 100=33\frac{1}{3}\%$