Find the next expression in the series: 

ABZ, ABBYZ, ABBBXYZ, ______?

Direction :Study the following information carefully and answer the questions given below:
Six friends M, N, O, P, Q and R live in a six- storey building. The ground floor is numbered 1 and the topmost floor is numbered 6. Q lives neither on the top floor nor on the bottom. There are two persons between the floors on which P and Q live. Only one floor is there between M and N. The floor on which R lives is below the floor on which Q lives. The floor of O is just above the floor on which N lives.

How many floors are there between P and R? 

Select the option that represents the letters that, when sequentially placed from left to right in the blanks below, will complete the letter series.
 _ M o N _ _ _ o M _ _ o _ _o M _ N o J o

3, 18, 15, 24, 35,?....

Select the letter that can replace the question0a mark (?) in the following series.
K, B, N, D, Q, F, T, H,?

Select the odd word/letters/number/number pair from the given alternatives.

Options:

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

RLV, PNS, NPP, ?, JTJ

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

QRM, PWD, OBU, NGL, ?