Select the combination of letters that when sequentially placed in the gaps of the given letters series will complete the series.
H _ _ EPCK _ _ CDEP _ KFHC _ EPC _ F

Pick an odd number in the given number series?

4 12 38 87 198

Select the figure that will come next in the following figure series.

380, 645, 557, 656, 762, 875, ?

In the following question, select the missing number from the given series.
1, 7, 3, 9, 6, 12, 10, 16, 15, ?

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

?, Vice President, Prime Minister, Deputy Prime Minister

2, 65, 7, 59, 12, 53, ?, ?

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

50 : 70 ::..?.... 90