Problema Solution
The cost price of 12 books is equal to the selling price of 10 books. Find the gain per cent
Answer provided by our tutors
let
c = the cost price per book
s = the sell price per book
gain = s - c
gain % = ((s - c)/c)*100
The cost price of 12 books is equal to the selling price of 10 books:
12c = 10s
s = (12/10)c
plug s = (12/10)c into gain % = ((s - c)/c)*100:
gain % = (((12/10)c- c)/c)*100
gain % = 20%
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