If A + B means A is the brother of B, A - B means A is the sister of B, and A × B means A is the father of B, what is the relationship of C if A + C × B?

C. C IS THE SON OF A

Identify the missing number in the series: 3, 7, 15, 31, ?

A. 63

If A=1, B=2, C=3, and so on, what is the code for the word 'CAT'?

B. 312

In the series 12, 15, 18, 21, 24, how many times does the number 21 appear?

A. 1

If in a certain code, 'CAT' is coded as 'DBU', how is 'DOG' coded in that code?

A. EPH