Multiple choice general knowledge

1,3,3,6,7,9,__,12,21

  1. 12

  2. 13

  3. 14

  4. 16
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The sequence consists of two interleaved patterns. Even positions (2nd, 4th, 6th, 8th) are 3, 6, 9, 12, adding 3 each time. Odd positions (1st, 3rd, 5th, 7th, 9th) are 1, 3, 7, ?, 21, the differences increase by 2: +2, +4, +6, +8. So 7+6=13 and 13+8=21 confirms the pattern.

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