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 salary of all workers in a workshop is $Rs. 12000$. The average salary of $7$ technicians is $Rs. 15000$ and the average salary of the rest is $Rs. 9000$. The total number of workers in the workshop is:

If the average of $m$ numbers is $n^{2}$ and that of $n$ numbers is $m^{2}$,then the average of $(m + n)$ numbers is

The average weight of $24$ students is $35\, kg$. If the weight of the teacher is added, the average increases by $400\, g$. What is the weight of the teacher in $kg$?

The average marks of a student obtained in Physics,Chemistry,and Biology is $70.$ If the student obtained $90$ marks in Mathematics,then the new average is

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)