Question

If a man purchases 11 oranges for Rs. 10 and sells 10 oranges for Rs. 11. How much profit or loss does he make? 

Answer 1

Cost price of 11 Oranges = Rs10 
Cost price of 110 Oranges = Rs 10*10 = Rs 100 
Selling Price of 10 Oranges = Rs11 
Selling Price of 110 Oranges = Rs11*11 = Rs121 
The man purchases 110 Oranges for Rs100 and sales them for Rs121 
So the profiit is 21%