Question

There were 35 students in a hostel, If the
number of students be increased by 7, the
expenditure on food increases by 42 per day
while the average expenditure of students is
reduced by 1. What was the initial expenditure
on food per day?
(a) 432 (b)442 (c) 420 (d) 400​

Answer 1

Answer:

420

Step-by-step explanation:

let the average expenditure of  students before increasing by 7be x

so,

expenditure of 35 students = 35x

expenditure of 42 students = 42(x-1)

according to the question ,

42(x-1) = 35x  + 42

⇒ 42x - 42 = 35x + 42

⇒ 42x -  35x = 42 + 42

⇒7x = 84

⇒ x = 12

initial expenditure = 35x = 35× 12

                              = 420