Correct Answer - Option 3 : 27.1 L
Given:
Barrel of grape juice = 100 L
10 L of juice replaced with milk = 3 times
Formula used:
Final Q = Initial Q × (1 - (volume removed/Initial Q)n
Here, n = Number of times volume taken out
Calculation:
Final Quantity = Initial Q × (1 - (volume removed/Initial Q)n
⇒ 100 × (1 – (10/100))3
⇒ 100 × (9/10) × (9/10) × (9/10)
⇒ 729/10
⇒ 72.9 L
Now, Milk added = 100 – 72.9
⇒ Milk added = 27.1
∴ 27.1 L of milk is to be added