A shopkeeper bought some sweets at 11 for a rupee. He bought an equal number of sweets at 10 for a rupee.He sold all the sweets at 8 for a rupee. Find his gain or loss per cent.

A shopkeeper bought some sweets at 11 for a rupee. He bought an equal number of sweets at 10 for a rupee.He sold all the sweets at 8 for a rupee. Find his gain or loss percent.

Cost price of 11+10=21 sweets is 1+1=Rs.2

So, cost price of each sweet=Rs. 2/21

Selling price of 8 sweets = Rs.1

Selling price of 1 sweet=Rs.1/8

Gain = 1/8 - 2/21=(21-16)/168=5/168

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