Equal whisky quantities mixed with water to reach a lower average price: Two lots of whisky priced at ₹ 22/L and ₹ 18/L are taken in equal volumes and mixed with water to make 50 L of mixture worth ₹ 16/L. How many liters of water are in the mixture?

Introduction / Context:
Water contributes no cost, so the total value of the mixture equals the value of just the whisky present. Using equal quantities of the two whisky lots simplifies the value calculation before matching the target average price over 50 L.

Given Data / Assumptions:

• Equal volumes of ₹ 22/L and ₹ 18/L whisky ⇒ each q L.
• Water volume = w L.
• Total volume = 2q + w = 50 L; mixture price = ₹ 16/L ⇒ total value = ₹ 800.

Concept / Approach:
Total value arises only from whisky: 22q + 18q = 40q. Set 40q = 800 to find q, then compute water as the remainder to 50 L.

Step-by-Step Solution:

Verification / Alternative check:
Value from whisky = 20*22 + 20*18 = 440 + 360 = 800; average over 50 L = 800/50 = ₹ 16/L, as required.

Why Other Options Are Wrong:
5, 15, or 20 L water would not yield the ₹ 16/L average given the whisky prices and equal whisky amounts.

Common Pitfalls:
Averaging prices without accounting for added water or forgetting water carries zero cost.

Final Answer:
10 L