Question

If the cost price of 15 pens is equal to the selling price of 20 pens, then the loss percent is

(a) 25%
(b) 20%
(c) 15%
(d) 10%

Answer 1

Let the cost price of one pen be ₹1.
Then, CP of 20 pens = ₹20
and SP of 20 pens = ₹15 (∵ SP of 20 pens = CP of 15 pens)

Therefore, CP is more than SP.

So, Loss = CP − SP
= ₹20 − ₹15
= ₹5

$$\begin{gathered} \mathrm{Loss}\mathrm{percent}=\frac{\mathrm{Loss}}{\mathrm{CP}}\times 100 \\ =\frac{5}{20}\times 100 \\ =25\% \end{gathered}$$

Hence, the correct option is (a).