Verbal Reasoning - Mental Ability Questions

Select the related word/letters/number from the given alternatives.
34 : 81 : : 23 : ?

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.

Brazil, Russia, ? , China, South Africa

A series is given, with one term missing. Choose the correct alternative from the given ones that will complete the series.

XXXXXO, XXXXOX, XXXOXX, XXOXXX, XOXXXX, ?

If 70$7 = -10, 50$5 = -10 and 40$8 = -5, then find the value of 10$2 = ?

Five girls are sitting facing towards the north. Rekha is between Shalini and Neetu. Pooja is to the immediate right of Neetu and Shalini is to the immediate right of Neha. Who is sitting in the middle?

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.

-1, 1, 4, 9, 16, ?

A series is given, with one number missing. Choose the correct alternative from the given ones that will complete the series.
-4, ? , 1, 3.5, 6, 8.5

A series is given, with one term missing. Choose the correct alternative from the given ones that will complete the series:

3,4,7,?,18,29,47