Question

A 40 litre mixture contains milk and water in the ratio 3:1. The quantity of water that must be added so that the ratio becomes 3:2 is

• A. 6 litres
• B. 8 litres
• C. 5 litres
• D. 10 litres

Hint:

Milk is unchanged; set water equal to two-thirds of the milk, then subtract what is already present.

Answer 1

The Correct Option is D

Step 1: Keep milk as 3 parts.
Milk is $30$ litres and equals $3$ parts, so one part is $10$ litres.
Step 2: Water must be 2 parts.
Water needed $=2\times10=20$ litres, and $10$ are already there, so add $20-10=10$.
\[\boxed{10\ \textrm{litres}}\]