The average age of $A, B, C, D$ five years ago was $45\, years.$ By including $x$, the present average age of all the five is $49\, years.$ The present age of $x$ is (in $years$)

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?

The average annual income (in $Rs.$) of certain agricultural workers is $S$ and that of other workers is $T$. The number of agricultural workers is $11$ times that of other workers. Then the average annual income (in $Rs.$) of all the workers is

The average of the test scores of a class of $'m'$ students is $70$ and that of $'n'$ students is $91.$ When the scores of both the classes are combined, the average is $80 .$ What is $n / m$ ?

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)