Choose the odd word/letters/number from the given alternatives

Four clusters have been given out of which three are alike in some manner and one is different. Select the one that is different.

Option

In each of the following questions. Select the related letter/ word/ number from the given alternatives.

WRITE : XSJUF : : OPEAC : ?

Which one set of letters when sequentially placed at the gaps in the given letter series shall complete it.

a_c_abb_a_bc_bc_ab 

Anand is son of Prema . Rajeev is brother of Prema . Neha is daughter of Rashmi . Neha is sister of Rajeev . How is Anand related to Rashmi ?

Find the missing number.
10, 100, 200, 310, ?

6 years ago, Raju's age was 2 years less than half of his brother's age, which was 20 years. What is his present age?

A series is given, with one term missing choose the correct alternative from the given ones that will complete the series.
1, 9, 25, 81, 329,  ?