Question

A man sells 12 articles for Rs. 80 gaining $33\frac{1}{3}\%$. Find the number of articles bought by a man for Rs. 90.

Answer 1

Given, S.P of $12$ articles $=Rs.80$

And for these $80$ articles, Profit $=33\frac{1}{3}=\frac{100}{3}$ %

So, Profit % $=\frac{S.P.-C.P.}{C.P.}\times 100=\frac{100}{3}$

$\Rightarrow \frac{80-C.P}{C.P}\times 100=\frac{100}{3}$

$\Rightarrow 80-C.P.=\frac{C.P.}{3}$

$\Rightarrow \frac{4}{3}C.P.=80$

$C.P.=60$

Hence, cost of $12$ articles $=Rs60$

And cost of $1$ article $=Rs.\frac{60}{12}=Rs5$

So, number of articles bought for $Rs.90=\frac{90}{5}=18$