Question

a man bought an article and sold it at the gain of 10% If he had bought it at 20% less and sold it for 10 rupees more he would have made profit of 40% find CP of an article

Answer 1

Let original CP of the article was X.
First Case:
SP = X + 5% of X = 105X/100
Second Case:
He bought article at 5% less.
CP = X - 5% of x = 95X/100
SP = (105X/100) - 1
Gain 10%.
SP - CP = Gain
(105X/100) - 1 - 95X/100 =  10% of 95X/100
10X/100 -1 =  95X/1000
0.1X - 1 =  0.095X
0.005 X = 1
X = 200
So, Original CP was Rs. 200