Choose the correct alternative which will complete the following series:

 

21, 55, 19, 50, 17, 45, ?

 

In the following question, select the missing number from the given series.

52, 41, 32, 25, ?, 17

In the following question, select the missing number from the given series.

2, 3, 4, 9, 16, 29, 54, ?

In the following question, select the missing number from the given series.

15, 22, 31, 42, 55, ?

In the following question, select the missing number from the given series.

13, 16, 20, 23, 27, ?

In the following series, one number is missing as shown by the ?. Select the missing number from the given options.

3, 8, 13, 18, ?

Select the number missing from the given series.

15, 20, 18, 23, ?, 26, 24

In the following question, select the missing number from the given series.

15, 22, 31, 42, 55, ?

In the following question, select the missing number from the given series.

13, 16, 20, 23, 27, ?