Question

A person buys milk of rs. 8.50 per litre and add water to it.He sells the mixture at the same price and earns a profit of 11.11%.Find out how much water did he add to each litre of milk

Answer 1

We know that 1/9  = 0.1111

Cost price  + profit    = selling price
Lets assume the cost price of milk is x, the calculation would be :

x + 1/9 x    = 1

10/9 x       = 1

x              = 9/10 

The amount of water would be : 1 - 9/10    = 1/10   = 10%