Which letter-cluster will replace the question mark (?) to complete the given series?

ZXE ZWD ZVC ? ZTA

Select the option that is related to the fifth letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster and the fourth letter-cluster is related to the third letter-cluster.
 COOK : DQPM :: DOWN : EQXP :: ONLY : ?

Which letter-cluster will replace the question mark (?) to complete the given series?

TYG, ?, PSM, NPP, LMS

A – B means ‘A is the mother of B’
 A * B means ‘A is the husband of B’
 A % B means ‘A is the brother of B’
 A $ B means ‘A is the sister of B’
 If I * J – K % L $ M * N, then how is I related to N?

Select the odd group of numbers. (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g.13 – Operations on 13 such as adding /subtracting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed)

Option

Select the set in which the numbers are related in the same way as are the numbers of the following sets. (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E. g. 13 – Operations on 13 such as adding / subtracting / multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed)

(0.20, 5, 25)
 (0.083, 12, 144)

Select the correct combination of mathematical signs to sequentially replace the * signs and to balance the given equation.
 25 * 4 * 6 * 2 * 17

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