Question

5) In a mess, there were 40 inmates. As 5 more have
joined, the average expenses were decreased by 1, but
the total expenses increased by 55. What was the total
initial expense of the mess?
A) 448
B) ₹800
C)₹880
D) 920​

Answer 1

Question :- In a mess, there were 40 inmates. As 5 more have joined, the average expenses were decreased by 1, but the total expenses increased by 55. What was the total

initial expense of the mess ?

A) 448

B) ₹800

C) ₹880

D) 920

Solution :-

Let us assume that, the average expenses was Rs.x

so,

→ Total initial expenses of the mess when their were 40 inmates = 40 * x = Rs. 40x

now,

→ Total new inmates = 40 + 5 = 45 inmates .

→ New average expenses = Rs. (x - 1)

then,

→ Total New expenses = Rs. 45(x - 1)

we have given that,

→ Total New expense - Total initial expense = Rs.55

→ 45(x - 1) - 40x = 55

→ 45x - 45 - 40x = 55

→ 5x = 55 + 45

→ 5x = 100

→ x = Rs.20 .

therefore,

→ The total initial expense of the mess = 40x = 40 * 20 = Rs.800 (Option B) (Ans.)