Fill in the blank space for the given series with the correct alternative.
$3, 15, 35, (\ldots), 99, 143$

To answer these questions, study the following arrangement of digits, letters and symbols carefully.

$6, N,P ,=,@, 7,1 ,\&, R, T, 3, L, ,B, \star, E ,4,\# ,8, G,H ,\$, 5, K,M ,?, 2, D,C$

If all the digits in the arrangement are deleted, which of the following will be midway between the $3^{rd}$ and the $15^{th}$ elements from the left end?

These questions are based on the following arrangement. Study it carefully and answer the questions.

$8 ,H ,\% ,3,7 ,T,A ,4 ,\# ,6 ,B,I ,@ ,R ,1 ,Q ,\star, L,E ,2 ,K ,\$ ,U ,5,9$

How many such symbols are in the above arrangement each of which is immediately followed by a number but not immediately preceded by another number?