A reservoir holds 2.5 million cubic metres of water. If the annual evaporation loss is 10% and the inflow is 3 million cubic metres per year, how much water (in cubic metres) is available for irrigation at the end of the year?

Step-by-step solution

1. Calculate evaporation loss: $10\%$ of $2.5000000=250,000$ m${}^3$.
2. Subtract loss from original volume: $2,500,000-250,000=2,250,000$ m${}^3$.
3. Add annual inflow: $2,250,000+3,000,000=5,250,000$ m${}^3$.
4. State the final volume.

Concept tested: Water resource management

Published 7 October 2026 · How this solution was prepared and checked