Choose the correct alternative for the missing term:
$2 A 11, 4 D 13, 12 G 17, ?$

Find the missing letters for the given series from the given alternatives:
$aab....bbaaa....cbba.....abc.....ba$

Which of the following will come in place of the question mark $(?)$ in the order given below?
$AC, EH, IM, MR, ?$

Choose the correct alternative for the missing terms in the series: $R, M, ?, F, D, ?$

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

$6,=, C,E, 3,8 ,G,L,M, 7, \star, @ ,P,R, 4, \#, \$, N,T, 5, S,V$

How many such digits are there in the arrangement each of which is immediately preceded by a letter?

Fill in the blank space for the given series with the correct alternative: $2, 6, 12, 20, 30, ?$