The average of $50$ numbers is $30.$ If two numbers,$35$ and $40$ are discarded,then the average of the remaining numbers is nearly.

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 diminishes by $Rs. 1$. Find the actual expenditure of the mess (in $Rs.$).

What will be the average of even numbers between $11$ and $63$?

The mean marks of $10$ boys in a class is $70 \%$,whereas the mean marks of $15$ girls is $60 \%$. The mean marks of all the $25$ students is

$A$ cricketer scored some runs in his continuous $9$ innings. He scored $100$ runs in his $10^{th}$ innings and this increased his average by $8$ runs. What was the average of his runs at the end of $10^{th}$ innings?

If the mean of $5$ observations $x, x+2, x+4, x+6$ and $x+8$ is $11,$ then the mean of the last three observations is