A letter series is given below in which some letter are missing. Select the  option that gives the letters that can fill these blanks in that order.
a_ca_bab_ad_abc_db

From the given options, select the shape which will come at the next position in the following series.

Find the next number in the given series.

3, 13, 31, ? , 91

In the following series find the missing numbers.
5, 13, 40, 104,?

In each of the following questions, a sequence is given, with one term missing. Choose the correct alternative from the given ones that will complete the series.
2, 3, 5, 9, 17, ?

In following question, a sequence is given, with one term missing. Choose the correct alternative from the given ones that will complete the series.
7, 12, 22, 42, 82, ?

Select the term that will come in the place of?

7, 11, 19, 31, ?  67

Which set of letters when sequentially placed at the gaps in the given letter series shall complete it?
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