Question

If A merchant purchases 9 pens & sells 8 pens at the cost price of 9 pens, then his profit per cent is:

• A. $5\frac{15}{17}$
• B. $8\frac{2}{3}$
• C. $12\frac{1}{2}$
• D. $11\frac{1}{9}$

Answer 1

The correct option is C $12\frac{1}{2}$

Let CP of 1 pen $=x$
CP of 9 pen $=9x$
CP of 8 pen $=8x$
$SP=8pen=9x$
% profit $=\frac{9x-8x}{8x}\times 100$
$\frac{100}{8}=12\frac{1}{2}$