Alphabet Test Reasoning Questions and Answers

Direction: Which one set of letters when sequentially placed at the gaps in the given letter series shall complete it.
ab_bba _ _bba _abb _ _a 

aa_baa_aaa_ba_ba

oru_o_uxor_x_rux 

_aa_ba_bb_ab_aab 

_bdd_ _d_ _ebd_e_dd

Direction: What should come in place of the questions mark (?) in the following letter series?
reoc, pgme, nikg, Ikii, ? 

XYZ, ABC, UVW, DEF, RST, GHI,_ ? 

deb, ijg, nol, ? , xyv 

AZBY, ? , EVFU, GTHS 

BDF, ? , PRT , WYA