Question

By selling a watch for $Rs.720$, Ravi loses $10$%. At what price should he sell it, in order to gain $15$%?

Answer 1

It is given that,
S.P of watch = $720$ Rs
Loss = $10$%
Therefore,
C.P $=\frac{100}{100-losspercentage}\times S.P$.
$=\frac{100}{(100-10)}\times 720$
$=\frac{100}{90}\times 720$

$=800$
C.P of watch is Rs. $800$.
It is given in the problem that, Profit expected = $15$%
C.P $=\frac{100}{100+\text{profit percentage}}\times S.P$.
$=\frac{100}{100+15}\times S.P.$

$⟹800=\frac{100}{115}\times S.P.$

$⟹S.P.=\frac{800\times 115}{100}$
$=\frac{92000}{100}=920$
Thus, the selling price will be $920$ to get a profit of $15\%$