Complete the series:
9, 13, 21, 37, ?

Question

Accepted Answer

1. Compute differences: $13-9=4$, $21-13=8$, $37-21=16$.
2. The differences double each time: $4,8,16,\dots$ so the next difference is $32$.
3. Add this to the last term: $37+32=69$.
4. Thus the correct choice is **(d)**.
FINAL_ANSWER: d

Answer

Answer

Answer