Question

If the ratio of alcohol and water in a mixture of 85 litres is 11 ∶ 6. How much water should be added to make the ratio 5 ∶ 3?
1. 2 litres
2. 3 litres
3. 4 litres
4. 5 litres
5. 6 litres

Answer 1

Correct Answer - Option 2 : 3 litres

Given:

Ratio	Alcohol ∶ Water
Old	11 ∶ 6
New	5 ∶ 3

 

Calculation:

Let the water that should be added be x litres

Initial quantity of alcohol = [11/(11 + 6)] × 85 litres

⇒ (11/17) × 85 litres

⇒ 55 litres

And, initial quantity of water = [6/(11 + 6)] × 85 litres

⇒ (6/17) × 85 litres

⇒ 30 litres

Now, [55/(30 + x)] = (5/3)

⇒ 11 × 3 = (30 + x)

⇒ x = 33 – 30

⇒ x = 3 litres

∴ 3 litres water should be added to make the ratio 5 ∶ 3.