A milkman has two cans. First containing 75% milk and rest water, whereas second containing 50% milk and rest water. How much mixture should he mix from each can so as to get 20 litres of mixture ,such that ratio of milk and water is 5 : 3 respectively ?

10 litre from 1st can, 10 litre from 2nd can

The correct answer is option (1) :10 litre from 1st can, 10 litre from 2nd can

Quantity of milk in 1st mixture $=\frac{75}{100}=\frac{3}{4}$ part.

Quantity of milk in 2nd mixture $=\frac{50}{100}=\frac{1}{2}$ part.

So Quantity of milk in final mixture $=\frac{5}{8}$ part.

LCM of $4, 2, 8=8$

$∴\frac{\text{Quantity of 2nd mix}}{\text{Quantity of 1s mix}}=\frac{\frac{1}{8}}{\frac{1}{8}}=1:1$

Hence, equal quantity of mixture from each can i.e 10 lit from 1st can so 10 lit from 2nd can should be mixed.