Question

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

Answer 1

Let assume cp of one pen =1₹
15 pens =15₹
Sp of 20 pens =cp of 15 pens=15₹
Cp of 20 pens acc to 1₹ for each =20₹
So loss =20-15=5₹
Loss%=(5/20)x100=5x5=25% loss

Answer 2

25% is the answer.
selling percentage =
$\frac{15}{20} \times 100 = 75percent \\ so \: lose = 100 - 75 = 25percent$