The average of the first $100$ positive integers is

If the average of $x$ and $\frac{1}{x} (x \neq 0)$ is $M$,then the average of $x^{2}$ and $\frac{1}{x^{2}}$ is

The mean of the marks obtained by $100$ students is $60$. If the marks obtained by one of the students was incorrectly calculated as $75$ whereas the actual marks obtained by him were $65$,what is the correct mean of the marks obtained by the students?

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

The average weight of $45$ students in a class was calculated as $36 \, kg$. It was later found that the weight of two students in the class was wrongly calculated. The actual weight of one of the boys in the class was $32 \, kg$,but it was calculated as $34 \, kg$,and the weight of another boy in the class was $45 \, kg$,whereas it was calculated as $40 \, kg$. What is the actual average weight of the $45$ students in the class? (in $kg$) (Rounded off to two digits after decimal)

The average of five numbers is $27$. If one number is excluded,the average becomes $25$. The excluded number is