The average of nine numbers is $50.$ The average of the first five numbers is $54$ and that of the last three numbers is $52 .$ Then the sixth number is?

The average score of Sachin after $25$ innings is $46$ runs per innings. If after the $26^{th}$ innings, his average runs increased by $2$ runs, then what is his score in the $26^{\text {th }}$ innings?

Three years ago the average age of a family of $5$ members was $27\, years.$ On addition of a child to the family, the present average age of the family is still $27 \,years.$ Find out the present age of the child. (in $years$)

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 $36$ students is $50 \,kg$. It was found later that the figure of $37 \,kg$ was misread as $73 \,kg.$ What is the correct average? (in $kg$)

$A , B , C$ and $D$ are four consecutive even numbers respectively and their average is $65 .$ What is the product of $A$ and $D ?$