Question

A milk man mixed 60 L of water and 40 L of milk and made a solution of 100 L.
He took 30 L of this mixture and again added some water to make 100 L of the solution. What is the ratio of milk to water in the solution?

• A. 7:19
• B. 9:19
• C. 7:18
• D. 5:21

Answer 1

The correct option is C 7:18

The initial solution of 100 L has 60 L of water and 40 L of milk.
This means that water and milk are in the ratio of
60:40 = 3:2

30 L of the solution is removed, which means that 70 L of solution is remaining.

Amount of water and milk in this solution:
Milk = $\frac{2}{2+3}\times 70$
= $\frac{2}{5}\times 70$ = 28 L

Water = $\frac{3}{2+3}\times 70$
= $\frac{3}{5}\times 70$ = 42 L

The 30 L solution was replaced with 30 L of water.

Now, total water is 30 + 42 = 72 L,
and total milk = 28 L

Ratio of milk to water is
28:72 = 7:18