Fill in the blank space for the given series with the correct alternative.
$165, 195, 255, 285, 345, (\ldots)$

How many such digits are there in the number $5231698$ each of which is as far away from the beginning of the number as when the digits are rearranged in ascending order?

Choose the correct alternative to complete the series: $c _ a c _ a a _ a a _ b e _ b c c$

Study of the following arrangement carefully and answer the questions given below.

$Q,E ,* ,P,M ,8 ,R,A ,@ ,C ,9 ,U,H,W, \# ,J,Z, ,S, \beta, Y,N ,5 ,\$ ,G,I,T$

Which of the following is exactly in the middle between the twelfth from the right and the seventh from the left end?

In the number $76534218$,each digit is replaced by the next digit (i.e.,$1$ is replaced by $2$,$2$ is replaced by $3$,and so on). After this,the digits are arranged in ascending order from left to right. Which digit will be fifth from the left end?

Find the missing letters for the given series from the given alternatives:
$abca.....bcaab....,aa.....caa....c$