In a hostel of 50 girls, there are food provisions for 40 days. If 30 more girls join the hostel, how long will these provisions last?

In a hostel of 50 girls, food is available = 40days

For 1 girl, food provision = 50× 40 = 2000days

Now, for (50 + 30) girls i.e. 80girls, the food provision =

⇒ 25 days

The food provision will last for 25 days, if 30 more girls join.