Question

Vijay sold a watch at a gain of 5%. Had he sold it for Rs 72 more, he would have gained 13%. Find out the cost price of the watch.

• A. Rs 900
• B. Rs 910
• C. Rs 870
• D. Rs832
• E. None of the above

Answer 1

The correct option is A Rs 900

Here, $S.P{.}_1-S.P{.}_2=-72,x=5,y=13.$
Using the formula,
$\frac{C.P.}{100}=\left(\frac{S.P{.}_1-S.P{.}_2}{x-y}\right)$
we get, $\frac{C.P.}{100}=\left(\frac{-72}{5-13}\right)$
$\Rightarrow C.P.=\frac{72}{8}\times 100=Rs900$