The mean of $50$ observations is $36$. If two observations $30$ and $42$ are removed,what is the mean of the remaining observations?

Let $M$ denote the median of the following frequency distribution. Then $20M$ is equal to:

Class	$0-4$	$4-8$	$8-12$	$12-16$	$16-20$
Frequency	$3$	$9$	$10$	$8$	$6$

The reciprocal of the mean of the reciprocals of $n$ observations is their

If the mean of $3, 4, x, 7, 10$ is $6$,then the value of $x$ is

In a class of $100$ students,there are $70$ boys whose average marks in a subject are $75$. If the average marks of the complete class are $72$,then what are the average marks of the girls?

The median of $10, 14, 11, 9, 8, 12, 6$ is