By selling 12 oranges for one rupee, a man loses 20%. How many for a rupee should he sell to get a gain of 20%?

A. 5
B. 8
C. 10
D. 15
Explanation:
He buys 12 oranges,
Then S.P = Rs. 1
Now, 80 : 1 :: 120 : X
X = 1 × 120/80 = 3/2 Rs. 3/2,
oranges sold = 12 Rs. 1,
oranges sold = (12 × 2/3) = 8