There are 35 students in a hostel. If number of students increased by 7, expenses of mess were incre

English

Gujarati

Hindi

4.Average

medium

There are $35$ students in a hostel. If the number of students increased by $7,$ the expenses of the mess were increased by $Rs.\,42$ per $day$ while the average expenditure per head decreased by $Rs.\,1$, Find out the actual expenditure of the mess. (in $Rs.$ )

A

$480$

B

$440$

C

$520$

D

$420$

Solution

Let, the original expenditure $=Rs. x$

Original average expenditure $=\frac{x}{35}$

New average expenditure $=\frac{x+42}{42}$

$\Rightarrow \frac{x}{35}-\frac{x+42}{42}=1 \Rightarrow x=420$

Original expenditure $=Rs. 420$

Standard 13

Quantitative Aptitude

Share

Similar Questions

The average age of $30$ girls is $1\, year.$ The average of first $18$ girls is $15\, year.$ Find out the average age of remaining $12$ girls?

medium

The average age of a group of $15$ students is $10 \,years.$ When $5$ more students joined the group, the average got increased by $1\, year.$ The age of the new student is (in $years$)

hard

The average weight of $3$ person is $65 \,kg$. If a fourth person having a weight of $45 \,kg$ joins the group, what is the average weight of the group ? (in $kg$)

medium

A cricketer, whose bowing average was $12.4$ runs/wicket takes $5$ wickets for $22$ runs in a match, thereby decreases his average by $0.4$ The number of wickets, taken by him before this match was

medium

The average of $5$ quantities is $6 .$ The average of three of them is $8 .$ What is the average of remaining two quantities?

medium