Choose or find odd word - Rival , Spouse , Partner , Colleague , Companion

A. RIVAL

Choose or find odd number - 49 , 63 , 77 , 81

D. 81

Choose or find odd number pair - (45 - 27) , (30 - 18) , (20 - 10) , (15 - 12)

C. 20 - 10

Choose or find odd pair of words - (Ammeter : Current) , (Hygrometer : Pressure) , (Odometer : Speed) , (Seismograph : Earthquakes)

B. HYGROMETER : PRESSURE

Choose or find odd number pair - (81 - 63) , (24 - 48) , (21 - 15) , (13 - 39)

A. 81 - 63