In the series,$6, 4, 1, 2, 2, 8, 7, 4, 2, 1, 5, 3, 8, 6, 2, 1, 7, 1, 4, 1, 3, 2, 8, 6$,how many pairs of successive numbers have a difference of $2$ each?

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

In a row of girls, Shilpa is $8^{th}$ from the left and Reena is $17^{th}$ from the right. If they interchange their positions, Shilpa becomes $14^{th}$ from the left. How many girls are there in the row?

How many $18$s are there in the following sequence which are immediately preceded by $9$ but not immediately followed by $7$?
$7, 1, 9, 1, 1, 7, 1, 8, 9, 1, 7, 1, 2, 1, 3, 1, 4, 5, 7, 1, 3, 9, 1, 7$

If the numbers from $5$ to $85$ which are exactly divisible by $5$ are arranged in descending order,which number would be at the eleventh place from the bottom?

If the position of the first and the sixth digits of the sequence of numbers $8, 9, 0, 3, 2, 1, 4, 6, 7, 5$ are interchanged,the second and the seventh and so on,which number would be seventh from the right end?