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
Your Answer: No Answer Given

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.