question_answer

Direction: Complete the series by choosing the correct option.

6, 18, 3, 21, 7, 56, ?

A)  35                   

B)         8                    

C)         63                   

D)         9

Correct Answer: B

Solution :

On the basis of the information given in the questions, we find that C and D can take three positions as shown in the diagram following the restriction that C and D cannot be together. Even terms in the series is product of two adjacent odd terms \[6\times 3=18\] \[3\times 7=21\] \[7\times ?=56\] \[?=8\]