A 100 litre pond contains stagnant water. A mosquito species lays 200 eggs per litre per day. If each egg hatches into a larva that consumes 1.5 ml of water before pupation, how much water remains after the larvae have eaten in 2 days?

Step-by-step solution

1. Step 1: Eggs laid per day = 200 eggs/litre × 100 litres = 20,000 eggs.
2. Step 2: Over 2 days, total eggs = 20,000 × 2 = 40,000 eggs.
3. Step 3: Each larva consumes 1.5 ml; total consumption = 40,000 × 1.5 ml = 60,000 ml = 60 litres.
4. Step 4: Initial water = 100 litres; remaining water = 100 litres – 60 litres = 40 litres.

Concept tested: Water consumption by mosquito larvae

Published 10 October 2026 · How this solution was prepared and checked