Question

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

Answer 1

Total cost price (C.P) $=156\times 20$

Total selling price (S.P)

$=8\times 156(1+\frac{10}{100})+12\times 156(1+\frac{20}{100})$

$=156(8+\frac{80}{100}+12+\frac{240}{100})$

$=156(20+3.2)=156\times 23.2$

$\Rightarrow$ Total Gain $=\frac{S.P-C.P}{C.P}\times 100$

$=\frac{156(23.2-20)}{156\times 20}\times 100$

$=\frac{3.2}{20}\times 100=16$%