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.
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