Fill in the blank space for the given series with the correct alternative.
$1, 2, 3, 6, 9, 18, (\ldots), 54$

Choose the correct alternative for the missing term in the series: $Z, U, Q, ?, L$

Choose the correct alternative to complete the series: $....tu....rt....s.....; .....usrtu.....$

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

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

Four of the following five are alike in a certain way based on the positions of the elements in the arrangement and hence form a group. Which one does not belong to the group?

Study the following arrangement carefully and answer the question given below:
$R, 4, E, J, 5, T, 1, A, M, Q, 3, 8, N, I, K, 7, W, F, 6, D, 9, U, 2, Y, V$
Which of the following is the sixth to the left of the eleventh from the left end of the above arrangement?

Find the missing letters for the given series from the given alternatives:
$.....bca......cca....ca.....b.....c$