Interview Q&A / Aptitude

1. A 60-litre mixture has alcohol and water in the ratio 2 : 1. How much water must be added to make the ratio 1 : 2?

   60 litres. The mixture has 40 L alcohol and 20 L water. Alcohol stays 40 L, and for 1 : 2 water must be 80 L. So add 80 - 20 = 60 litres of water.

   BeginnerQuick answer1 min read
2. Two vessels contain milk and water in the ratios 3 : 1 and 5 : 3. If equal quantities from both are mixed, what is the ratio of milk to water?

   11 : 5. Milk fractions are 3/4 and 5/8. Taking one litre from each gives milk 3/4 + 5/8 = 11/8 litres out of 2, so milk is 11/16 and water 5/16 of the mixture.

   BeginnerQuick answer1 min read