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?
Let the number of days is 
Total number of girls = 50 + 30 = 80
Girls | 50 | 80 |
Time (days) | 40 | x |
Therefore the number of days the food will last is 25 days
9