Question

1000 soldiers in a fort had enough food for 20 days. But some soldiers were transferred to another fort and the food lasted for 25 days. How many soldiers were transferred ?

Answer 1

For $20$ days fort has food for $1000$ soldiers
For $1$ days fort has food for $1000\times 20$ soldiers
For $25$ days fort has food for $\frac{1000\times 20}{25}$ soldiers
=$800$soldiers
$\therefore 1000-800=200$ soldiers were transferred.