The average weight of $24$ students is $35\, kgs.$ If the weight of teacher is added the average increased by $400\, gms$. What is the weight of the teacher? (in $kg$)

In a class, there are $20$ boys whose average age is decreased by $2$ $months,$ when one boy aged $18\, years$ in replaced by a new boy. The age of the new boy is

The average salary of $20$ workers in an office is $Rs. \,1900$ per $month.$ If the manager's salary is added, the average becomes $Rs. \,2000$ per $month.$ The manager's annual salary (in $Rs.$) is

The average weight of $8$ sailors in a boat is increased by $1\, kg$ if one of them weighting $56\,kg$ is replaced by a new sailor. The weight of the new sailor is (in $kg$)

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?

The average of $13$ results is $60 .$ If the average of first $7$ results is $59$ and that of last $7$ results is $61,$ what will be the seventh result $?$