Question

By selling 100 mangoes a fruit seller gains the s.p. of 20 mangoes .find his gain%.

Answer 1

Solution:-
Let the selling price of each mango = x Rs.
Then selling price of 100 mangoes = 100x Rs.
Gain = selling price of 20 mangoes = 20x Rs.
Cost price of 100 mangoes = selling price - gain
⇒ 100x - 20x = 80x
Gain percentage = (gain×100)/cost price
⇒ (20x × 100)/80x
Gain percentage = 25 % 
Answer.

Answer 2

SP=selling price
CP=cost price
G=gain
GP=gain percentage
let the sp of each mango rs.=x
than sp of 100 mangoes =100x rs.
g=sp of 20 mangoes 20x rs.
cp of 100 mangoes=sp-g
=100x-20x=80x
gp=(g×100)/(cp)=(20x×100)/80x
gp=25% answer
i hope this answer is help you