The average expenditure of a man for the first five months is $Rs.\, 120$ and for the next seven months is $Rs. \,130$ . His monthly average income in $Rs.$ if he saves $Rs. \,290$ in that year, is

There were $35$ students in a hostel. If the number of students increases by $7,$ the expenses of the mess increase by $Rs. \,42$ per $day$ while the average expenditure per head decreases by $Rs.\, 1 .$ Find the original expenditure of the mess in $Rs.$

The daily maximum temperature in Delhi, for $7$ consecutive days in $May \,1988 ,$ were $42.7^{\circ} C , 44.6^{\circ} C$, $42.0^{\circ} C , 39.1^{\circ} C , 43.0^{\circ} C , 42.5^{\circ} C$ and $38.5^{\circ} C$. Find out the average daily maximum temperature. (in $^{\circ} C$)

The average of five consecutive positive integers is $n$. If the next two integers are also included, the average of all these integers will

A student was asked to find the arithmetic mean of the numbers $3,11,7,9,15,13,8,19,17,21,14$ and $x$. He found the mean to be $12 .$ What should be the number in place of $x ?$

The average of $X_{1}, X_{2}$ and $X_{3}$ is $14 .$ Twice the sum of $X_{2}$ and $X_{3}$ is $30 .$ What is the value of $X_{1} ?$