Question

A mixture contains acid and water in the ratio of 6 : 1. On adding 12 litres of water to the mixture, the ratio of acid to water becomes 3 : 2. The quantity of water (in litres) in the original mixture was:

• A. 3.5
• B. 6
• C. 4
• D. 5

Answer 1

Answer:

C. 4

Solution:

Given:

Acid and Water in ratio = 6 : 1

Water added to the mixture = 12 litres

The Final ratio of acid to water = 3 : 2

Calculation:

Let the amount of acid and water initially be 6x and x 

The initial ratio of acid to water = 6x : x

Adding water to mixture litres =  x + 12

According to question,

$[\frac{6x}{(x + 12)}] = \frac{3}{2}$

⇒ 12x = 3x + 36

⇒ 9x = 36

⇒ $x = \frac{36}{9} = 4$

∴ The quantity of water in the original mixture is 4 litres