Sunita pours 20 litres of a milk–water mixture in the ratio $3 : 1$ and 30 litres of a milk–water mixture in the ratio $3 : 2$ into one large pot. What is the ratio of milk to water in the pot?

Explanation

1. 01

   First mixture: milk = $\frac{3}{4} \times 20 = 15$, water = 5 litres.

2. 02

   Second mixture: milk = $\frac{3}{5} \times 30 = 18$, water = 12 litres.

3. 03

   Total: milk 33, water 17, so milk : water = $33 : 17$.