Pandit Madan Mohan Malviya is credited with popularising

Choose the correct alternative from the given ones that will complete the series.

3.5 , ?,  8.3, 10.7, 13.1 , 15.5

What will come in place of question mark [?] following the same pattern as given below?

What will come in the place of question mark?

Find the missing number.

In the following expression find the missing term:  

Study the given pattern carefully and select the number that can replace the question mark (?) in it.  

First row: 4, 6, 18

Find the missing term in the following series:

43 44 ? 69 185

Select the option that is related to the third number in the same way as the second number is related to the first number.

15 : 5 :: 26 : (?)