Choose or find odd word - Commander , Commodore , Brigadier , Admiral

C. BRIGADIER

Choose or find odd number pair - (6 - 15) , (21 - 43) , (25 - 51) , (29 - 59)

A. 6 - 15

Choose or find odd pair of words - (Principal : School) , (Soldier : Barrack) , (Artist : Troupe) , (Singer : Chorus)

A. PRINCIPAL : SCHOOL

Choose or find odd word - Galileo , Copernicus , Columbus , Bhaskara , Aryabhatta

C. COLUMBUS

Choose or find odd letter group - DSFU , PGRI , HRGQ , BUDW , INKP

C. HRGQ