The average salary per head of all workers of an institution is $Rs. \,60\,.$ The average salary per head of $12$ officers is $Rs. \,400 .$ The average salary per head of the rest is $Rs.$ $56 .$ Then, the total number of workers in the institution 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 temperature from Monday to Thursday is $48^{\circ} C$ and from Tuesday to Friday is $52^{\circ} C$. If the temperature on Monday is $42^{\circ} C$, what was it on Friday? (in $^{\circ} C$)

The average of six numbers is $32 .$ If each of the first three numbers is increased by $2$ and each of the remaining three numbers is decreased by $4,$ then the new average is ?

Find average of all prime numbers between $60$ and $90.$

A number, $x,$ equals $80 \%$ of the average of $5,7,$ $14$ and a number $y$. If the average of $x$ and $y$ is $26$ then value of $y$ is