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

In a row of ten boys, when Rohit was shifted by two places towards the left, he became seventh from the left end. What was his earlier position from the right end of the row?

Akshay is $16^{th}$ from the left end in a row of boys and Vijay is $18^{th}$ from the right end. Avinash is $11^{th}$ from Akshay towards the right end and $3^{rd}$ from Vijay towards the right end. How many boys are there in the row?

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?

If the numbers from $1$ to $45$ which are exactly divisible by $3$ are arranged in ascending order,with the minimum number at the top,which number would be at the ninth place from the top?

Ravi is $7$ ranks ahead of Sumit in a class of $39$ students. If Sumit's rank is $17^{th}$ from the last, what is Ravi's rank from the start (in $^{th}$)?