A series is given with one term missing. Choose the correct option from the given options and complete the series.
5, 6, 9, 15, ?, 40

Which of the following numbers will replace the question mark (?) in the given series?

67, 78, 71, 82, 75, 86, ?

Which of the following numbers will replace the question mark (?) in the given series?

5103, 1701, 567, ?, 63, 21

Which of the following numbers will replace the question mark (?) in the given series
 13, 14, 23, 48, 97, 178, ? 

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.

RS, ZA, HI, ?

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.

PON, LKJ, GFE, ?

2, 10, 30, 68, ?

Which of the following numbers will replace the question mark (?) in the given series?
 1724, 1716, 1689, 1625, 1500, ?