Question

if a cost price of 15 pen is equal to selling price of 20 find the gain or loss percent

Answer 1

Let the CP of 1 pen be Rs.x.
Therefore, the CP of 15 pens = Rs.15x
CP of 15 pens = SP of 20 pens
SP of 20 pens = Rs.15x
SP of 1 pen. = Rs.15x/20
= ₹3x/4

Loss. = CP - SP
= ₹x - ₹3x/4
= ₹x/4

Loss percentage = loss/ CP *100
= (₹x/4) / ₹x *100
= 25

Ans. = The loss percentage is 25%.

Answer 2

done step wise hope it help