Question

A mixture of liquids A and B in a jar is in the ratio of 4 ∶ 1. If 10 liters are taken out of that mixture and the same amount of liquid B is added in its place, then the ratio of the mixture will be 2 ∶ 3. Accordingly, what was the amount of liquid A in the initial mixture in the jar?
1. 20 liters
2. 10 liters
3. 16 liters
4. 15 liters

Answer 1

Correct Answer - Option 3 : 16 liters

Given 

Ratio of liquids A and B in jar = 4 : 1 

After addition of liquid B the ratio become = 2 : 3 

Calculation 

Initially (A : B) = 4 : 1 --(1)

Final (A : B) = 2 : 3 ---(2)

In both condition the amount of A is same 

So, eq (2) multiplied by 2 

Final (A : B) = 4 : 6

change in B = 10 L

⇒ 6x - x = 10 

⇒ x = 2 

So Total liquid in jar = 10x = 20 litres 

then Amount of A in jar(initially) = 20/5 × 4 = 16 litres 

∴ the required answer is 16 litres