A man buys 10 articles for Rs 8 and sells them at Rs 1.25 per article. His gain percent is:

The correct option is B $56\frac{1}{4}\%$
Cost price of 10 articles (C.P.) =Rs 8
Selling price of 10 articles (S.P.) $=1.25\times 100$
=Rs 12.50
Profit =S.P =C.P. =12.50-8 =Rs 4.50.
$\therefore$ Gain % $=\frac{Gain\times 100}{C.P}=\frac{4.50\times 100}{8}=56\frac{1}{4}\%$