Let the number of students in the hostel be x
Quantity of rice consumed by each student = 400 gm.
So, daily rice consumption in the hostel mess = 400 (x).
But, daily rice consumption = 50 kg = 50 × 1000 = 50000gm [since 1 kg = 1000gm].
According to the question,
⇒ 400x = 50000
Dividing both sides by 400, we get
⇒ 400 x/400 = 50000/400
⇒ x = 125
Thus, 125 students have their meals in the hostel mess.