By selling an article for Rs. 100, a man gains Rs. 15. Then his gain percent is

$\par&space;S.P.&space;=&space;Rs.&space;100,&space;gain&space;=&space;Rs.&space;15$

$\par&space;C.P.&space;=&space;Rs.&space;(100&space;-&space;15)&space;=&space;Rs.&space;85$

$\par&space;Gain\%&space;=$ $\left(\frac{15}{85}\times&space;100)\right)\%&space;=$  $\frac{300}{17}\%&space;=$ $17\frac{11}{17}\%$