In following question, a number series is given with one term missing. Choose the correct alternative that will same pattern and fill in the blank spaces. -
3, 7, 15, 31, 63,
Answer: C. 127
Each number in the series is the preceding number multiplied by 2 and then increased by 1.
Thus, (3 * 2) + 1 = 7,
(7 * 2) + 1 = 15,
(15 * 2) + 1 = 31 ans so on.
.'. Missing number = (63 * 2) + 1 =127.