Identify the missing letters in the series: b, d, f, h, ?

A. J

In a coding system, 'HELLO' is coded as 8, 5, 12, 12, 15. If 'WORLD' is coded as 23, 15, 18, 12, 4, what is the code for 'GOOD'?

A. 7, 15, 15, 4

Identify the missing letter in the series: Z, X, V, T, ?

B. S

In a family of six members A, B, C, D, E, and F, A is the father of B. C is the mother of B and D. E is the sister of B. F is the brother of D. How is E related to F?

A. SISTER

Complete the series: m, n, o, p, ?, r

A. Q