Question

Nandlal bought $20$ dozen notebooks at $Rs.156$ per dozen.He sold $8$ dozens of them at $10\%$ gain and the remaining $12$ dozens at $20\%$ gain.What is his gain per cent in the whole transaction?

Answer 1

Nandlal bought $20$ dozen Notebooks at $Rs.156$ per dozen

Total purchasing price $=156\times 20$

$=3120$

He sold $8$ dozen at $10\%$ profit + $12$ dozen at $20\%$ profit

$[156\times 8+\frac{156\times 8\times 10}{100}]+[156\times 12+\frac{156\times 12\times 20}{100}]$

$\Rightarrow 1248+\frac{1248}{10}+1872+\frac{3744}{10}$

$\Rightarrow \frac{3120+1248+3744}{10}$

$\Rightarrow 3619.20$

So selling price $=3619.2$

profit = selling price -purchasing price

$=3619.2-3120$

$=499.2$

profit $\%=\frac{499.2\times 100}{3120}$

$=16\%$ Ans