29. Find out the wrong number in the series.: 3, 7, 15, 39, 63, 127, 255, 511 September 6, 2025 by Admin [A]. 7 [B]. 15 [C]. 39 [D]. 63 ✅ The correct answer is option C. Go on multiplying 2 and adding 1 to get the next number. So, 39 is wrong.