A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
I, L, O, R, ?

In the given figure select the number that can replace the question mark (?).

Select the option that can replace the question mark (?) in the following series. 

B, D, G, L, S, ?

Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
GF, KI, OL, SO, ?

Find the missing number?

Find the missing number from the given alternatives.

Find the missing number?
2, 15, 41, 80, ?

Find  the missing Number .