Question

Rajat sold an article for rs 56 which cost him rs x . If he had gained x% on his outlay, what was his cost?

Answer 1

sp of the article is rs 56
cp of the article is rs x
profit(gain )= sp ₋ cp
⇒sp - cp =56 - x
gain %=gain*100/cp⇒(56-x)*100/cp⇒(56 - x)* 100/x=x            (given gain%=x)
(56 - x )*100=x²
⇒x²+100x - 5600
⇒simplify this equation you will get the value of x
⇒you  will get negative and positive value for x then take x as positive value

Answer 2

selling price (s.p ) = 56 Rs.
cost price ( c.p ) = x Rs.
gain = x%
i.e., profit = x/100
w.k.t.
Profit = S.P - C.P
x/100 = 56 - x
x/100 + x = 56
x (1/100 + 1 ) = 56
x ( 101/100 ) = 56
x = 56 × 100/101
x = 5600 / 101
x = 55.44 Rs.