Question

A shopkeeper purchases 11 knives for rs 10 and sells them at the rate of 10 knives for rs 11. how much profit does he earn?

Answer 1

the cost of one knife he paid = 0.909
and the cost he selled = 1.1
so profit/knife= 1.1-0.909=0.11
for total profit for 11 knife=0.11*11=RS 1.21

Answer 2

The profit he earned is 21%  

Step-by-step explanation:

Number of knives the shopkeeper purchased = 11

The cost at which he purchased 11 knives = 10

Cost price of one knife = 10/11 = 0.909

Later he sells them at the rate of 10 knives for Rs.11

10 knives = Rs.11

1 knife = 11/10 = 1.1

Profit is incurred when the selling price is more than the price at which the item is brought.

Profit for one knife = Selling price of one knife - Cost price of one knife

= 1.1 - 0.909 = 0.191

Therefore, profit incurred for 11 knives = 11 $\times$ 0.191 = 2.101  

On making it in percentage is 21%