Question

Solve the word problem.

$25$ people in a hostel have enough food for $15$ days. How long would the food last if $5$ people leave the hostel?

Answer 1

$25$ people in a hostel have enough food for $15$ days.

$\therefore 1$ person, there is a food for $(25\times 15)\mathrm{days}$

$\because$$5$ people left, there are $20$ people in a hostel now.

For $20$ people, there is food for $=\frac{25\times 15}{20}=18\frac{3}{4}\mathrm{days}$

Hence. the food will lasts for $18\frac{3}{4}\mathrm{days}$.