The average of a non-zero number and its square is $5$ times the number. The number is
$9$
$17$
$29$
$295$
Average rainfall on Monday, Tuesday, Wednesday and Thursday is $420.5\, cm$ and average on Tuesday, Wednesday, Thursday and Friday is $440.5\, cm .$ If the ratio of rainfall for Monday and Friday is $20: 21,$ find the rainfall in $cm$ on Monday and Friday.
Average age of $15$ students of a class is $15\, years.$ Out of these the average age of $5$ students is $14 \,years$ and that of the other $9$ students is $16\, years.$ The age of the $15^{th}$ student is (in $years$)
The average of consecutive numbers is $n .$ If the next two consecutive numbers are also included, the average of the five numbers will
The average of first nine prime numbers is
A batsman score $98$ runs in the $17^{\text {th }}$ match of his career. His average runs per match increase by $2.5$ What is his average before the $17^{\text {th }}$ match?