Category: Fluid Reasoning
Difficulty: Hard
Result: Wrong
20. Which number comes next in the series?
1, 1, 3, 6, 12, 22, 39, 67, 113, 188, ?
- 292
- 301
- 302
- 310◀ Correct Answer
- 311
This question tests your ability to recognize and extend numerical patterns in a sequence. The given sequence is: 1, 1, 3, 6, 12, 22, 39, 67, 113, 188, ?
To find the next number in the series, we first analyze the differences between consecutive terms:
- 1 to 1: +0
- 1 to 3: +2
- 3 to 6: +3
- 6 to 12: +6
- 12 to 22: +10
- 22 to 39: +17
- 39 to 67: +28
- 67 to 113: +46
- 113 to 188: +75
Observing these differences: 0, 2, 3, 6, 10, 17, 28, 46, 75.
Next, analyze the pattern in these differences by finding the differences between them:
- 2 - 0 = 2
- 3 - 2 = 1
- 6 - 3 = 3
- 10 - 6 = 4
- 17 - 10 = 7
- 28 - 17 = 11
- 46 - 28 = 18
- 75 - 46 = 29
The second-level differences are: 2, 1, 3, 4, 7, 11, 18, 29.
Notice that each second-level difference is the sum of the two preceding second-level differences:
- 1 = 2 - 1
- 3 = 1 + 2
- 4 = 3 + 1
- 7 = 4 + 3
- 11 = 7 + 4
- 18 = 11 + 7
- 29 = 18 + 11
Following this pattern, the next second-level difference would be 18 + 29 = 47.
Therefore, the next first-level difference is 75 + 47 = 122.
Finally, adding this difference to the last term in the sequence: 188 + 122 = 310.
Thus, the correct answer is 310.