A student buys a pen for Rs 90 and sells it for Rs 100. Find his gain and gain percent.
Cost price of pen = Rs. 90
Selling price of pen = Rs. 100
Hence,
Gain = selling price – cost price = 100 – 90 = Rs. 10
Gain% = 
1
A student buys a pen for Rs 90 and sells it for Rs 100. Find his gain and gain percent.
Cost price of pen = Rs. 90
Selling price of pen = Rs. 100
Hence,
Gain = selling price – cost price = 100 – 90 = Rs. 10
Gain% =