Question

There are 81 litres pure milk in a container. One-third of milk is replaced by water in the container. Again one third of mixture is extracted and equal amount of water is added. What is the ratio of milk to water in the new mixture?

A) 1:2
B) 1:1
C) 2:1
D) 4:5

Answer 1

To find the ratio of milk to water in the new mixture, divide the amount of milk and water in the container after each step. The ratio of milk to water is 1:1.

Step-by-step explanation:

To find the ratio of milk to water in the new mixture, we can first calculate the amount of milk and water in the container after each step.

Step 1: One-third of 81 litres of pure milk is replaced by water, which is 81/3 = 27 litres of milk replaced by water. So, we now have 81-27 = 54 litres of milk and 27 litres of water in the container.

Step 2: One-third of the mixture is extracted, which is (1/3) * (54+27) = 27 litres. The same amount of water, 27 litres, is added. So, the final mixture contains 54 litres of milk and 27+27 = 54 litres of water.

The ratio of milk to water in the new mixture is 54:54, which simplifies to 1:1. Therefore, the answer is B) 1:1.