In the first $30$ overs of a cricket match, the run rate was $5.2 \,runs/over.$ What is the required run rate in the remaining $20$ overs to reach the target of $280$ runs?

Average age of $A, B$ and $C$ is $84\, years.$ When $D$ joins them the average age becomes $80\, years.$ A new person, $E,$ whose age is $4 \,years$ more than $D,$ replaces $A$ and the average of $B, C, D$ and $E$ becomes $78\, years.$ What is the age of $A$ ? (in $years$)

The average of three numbers is $154 .$ The first number is twice the second and the second number is twice the third. The first number is

Average weight of $3 \,cm$ men $A , B , C$ is $84 \,kg$. Another man $D$ joins the group and the average now becomes $80 \,kg$. If another man $E$ whose weight is $3 \,kg$ more than that of $D$ replaces $A$ then the averageweight of $B , C , D$ and $E$ becomes $79\, kg .$ The weight of $A$ in $kg$ is

The average weight of $5$ persons, sitting in a boat, is $38 \,Kg$. If the average weight of the boat and the persons sitting in the boat is $52 \,Kg$, what is the weight of the boat? (in $kg$)

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