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?

If the average of $6$ consecutive even numbers is $25 ,$ the difference between the largest and the smallest number is

There are three baskets of fruits. The $1^{st}$ basket has twice the number of fruits in the $2^{nd}$ basket. The $3^{rd}$ basket has three-fourths of the fruits in the first. The average of the fruits in all the baskets is $30 .$ What is the number of fruits in the first basket ?

A cricketer had a certain average of runs for his $64$ innings. In his $65^{th}$ innings, he is bowled out for no score on his part. This brings down his average by $2$ runs. His new average of runs is?

The average marks of a student in four subjects is $75 .$ If the student obtained $80$ marks in the $5^{\text {th }}$ subject then the new average 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