Find out the missing letters for the given series from the given alternatives.
$adb.....ac.....da....cddcb.....dbc....cbda$

Which number will come next in the following series?
$2, 1, 2, 1, 3, 2, 1, 3, 4, 2, 1, 3, 4, 5, 2, 1, 3, 4, 5, 6, 2, 1, 3, 4, 5, ?$

Choose the correct alternative to fill in the blanks in the series: $....bbca....bcca......ac.....a...cb$

Fill in the blank space for the given series with the correct alternative.
In the series $2, 6, 18, 54, \ldots,$ what will be the $8^{th}$ term?

Study carefully the following arrangement of letters,digits,and symbols to answer the question:
$M, 7, \&, 8, L, P, @, Q, N, \beta, T, Y, 3, 2, =, E, 4, 9, \#, G, H, 5$
How many such letters are there in the arrangement,each of which is immediately followed by a number?

Find the wrong number in the series.
$3, 8, 15, 24, 34, 48, 63$