Insert the missing number
6, 7, 9, 13, 21, ... Select the correct option.
A) 25  B) 29  C) 37  D) 32  E) 30
Difference between two numbers in the series is multiplied by 2 to get the next number   6,7 ...Difference is 1   7,9 Difference is 2   9,13 difference is 4   13,21 Difference is 8   21, 37 Difference is 16   ANSWER:37
<result>C</result>
Insert the missing number
6, 7, 9, 13, 21, ...