There were 45 students in a hostel. If 9 new students came, the expenses of mess increase by Rs. 25 per day while the average expenditure per head decrease by Rs. 1. Find the original exp. of mess?

Option 1 : Rs. 395

**Given:**

Total students = 45

**Formula used:**

Sum of element = average × no. of element

**Calculation:**

Let the average expenditure be Rs. x

According to the question:

Total expenditure = 45x + 25 = 54(x – 1)

⇒ 45x + 25 = 54x – 54

⇒ 45x – 54x = -54 – 25

⇒ 9x = 79

⇒ x = 79/9

Now,

Total expenditure = (79/9) × 45 = Rs. 395

**∴ The original exp. of mess is Rs. 395.**