Multiple choice

What will come in place of question mark?

1, 3, 7, 15, 31, 63, ?

  1. 95

  2. 127

  3. 128

  4. 79

  5. 71

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As it is clear from the series, every term of the series is added to the increasing powers of 2 to get the next term.

1 + 21 = 3 3 + 22 = 7 7 + 23 = 15 15 + 24 = 31 31 + 25 = 63 Similarly, 63 + 26 = 127