Question

a man bought 25 books and sold 20 book of the price of 25 books find the loss or gain percent

Answer 1

Let the CP of one book be 10 rupees

then,  CP of 25 books =(10*25) = 250 rupees

also, CP of 20 books =(10*20) = 200 rupees

Hence, CP of 20 books (200) = SP of 20 books (250)

Gain %

= (50/200*100)

= (50/2)

=25% gain

(Hope you like this)