a container has 500 liters of milk from the container 100

Question

a container has 500 liters of milk from the container 100 liters of milk is taken out and is replaced by water how much milk is left in the container now after three such processes

Answer 1

After one of the processes, you have 400 liters of milk mixed with 100 liters of water. That's 400/500 = 4/5 milk and 100/500 = 1/5 water.

 

During the second process, the 100 liters you take out is 4/5 milk and 1/5 water, leaving you with 400 - 100(4/5) = 400 - 80 = 320 liters of milk mixed with 100 - 100(1/5) = 100 - 20 = 80 liters of water. Adding 100 liters of water back in leaves you with 320 liters of milk and 180 liters of water. That's 320/500 = 16/25 milk and 180/500 = 9/25 water.

 

During the third process, the 100 liters you take out is 16/25 milk and 9/25 water, leaving you with 320 - 100(16/25) = 320 - 64 = 256 liters of milk. You needn't calculate the liters of water.