A school camp has food for 120 students for 25 days. After 5 days, 40 more students join. For how many more days will the remaining food last?

Explanation

1. 01

   After 5 days the food left would feed 120 students for 20 days = $120 \times 20 = 2{,}400$ student-days.

2. 02

   Now there are 160 students, so it lasts $2{,}400 \div 160 = 15$ more days.