Multiple choice general knowledge math & puzzles

The missing term in the sequence 3, 7, 15, 31, ____ , 127 is:

  1. 63

  2. 71

  3. 92

  4. 113
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sequence follows the pattern 2n + 1. Starting with 3: 3×2+1=7, 7×2+1=15, 15×2+1=31. Therefore, 31×2+1=63, and 63×2+1=127, confirming the pattern.

AI explanation

To find the missing term in the given sequence, let's analyze the pattern:

Starting with the first term, 3, each subsequent term is obtained by doubling the previous term and then subtracting 1.

Here's the step-by-step explanation:

First term: 3 Second term: (3 * 2) - 1 = 6 - 1 = 5 Third term: (5 * 2) - 1 = 10 - 1 = 9 Fourth term: (9 * 2) - 1 = 18 - 1 = 17 Fifth term: (17 * 2) - 1 = 34 - 1 = 33 Sixth term: (33 * 2) - 1 = 66 - 1 = 65

Therefore, the missing term in the sequence 3, 7, 15, 31, ____, 127 is 65.

Looking at the options:

A. 63 - This option is incorrect because the missing term is 65, not 63. B. 71 - This option is incorrect because the missing term is 65, not 71. C. 92 - This option is incorrect because the missing term is 65, not 92. D. 113 - This option is incorrect because the missing term is 65, not 113.

The correct answer is A) 63.

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