Question

The cost price of 5 pens is the same as the selling price of 4 of them. Find the gain percent.

Answer 1

Let the S.P. of 4 pens = Rs.x

∴ S.P. of 1 pen = Rs.`x/(4)`

C.P. of 5 pens will also be Rs. x

∴ C.P. of 1 pen = Rs.`x/(5)`

As S.P. > C.P.
∴ Profit
= S.P. - C.P.

= Rs.`(x/4 - x/5)`

= Rs. `((5x - 4x)/20)`

= Rs.`x/(20)`

Now, Profit%
= `"Profit"/"C.P." xx 100`

= `(x/20)/(x/5) xx 100`

= `x/(20) xx (5)/x xx 100`
= 25%.