In a class of $60$ students, where girls are twice the number of boys, Kamal ranked $17^{th}$ from the top. If there are $9$ girls ahead of Kamal, how many boys are after him in rank?

Count each $7$ which is not immediately preceded by $5$ but is immediately followed by either $2$ or $3.$ How many such $7's$ are there?
$5, 7, 2, 6, 5, 7, 3, 8, 3, 7, 3, 2, 5, 7, 2, 7, 3, 4, 8, 2, 6, 7, 8$

In the series,$6, 4, 1, 2, 2, 8, 7, 4, 2, 1, 6, 3, 8, 6, 2, 1, 7, 1, 4, 1, 3, 2, 8, 6$,how many pairs of alternate numbers have a difference of $2$?

Thirty-six vehicles are parked in a parking lot in a single row. After the first car,there is one scooter. After the second car,there are two scooters. After the third car,there are three scooters,and so on. Work out the number of scooters in the second half of the row.

$A$ bus for Trivandrum leaves every $30 \,minutes$ from a bus stand. On enquiring,the clerk told a passenger that the bus had already left ten minutes ago and the next bus will leave at $9:35 \,am$. At what time did the clerk give this information to the passenger?

In the sequence $7, 8, 9, 7, 6, 5, 3, 4, 2, 8, 9, 7, 2, 4, 5, 9, 2, 9, 7, 6, 4, 7$,how many $7$'s are preceded by $9$ and followed by $6$?