A man buys 10 articles for Rs. 8 and Sells them at the rate of Rs. 1.25 per article. His gain is:________?

A. 20%
B. 50%
C. 19 ½ %
D. 56 ¼ %
Explanation:
C.P of 10 articles = Rs. 8
S.P of 10 articles = Rs. (1.25 × 10) = Rs. 12.50
Gain = (4.5/8 × 100)% = 56 ¼%