Which number does not belong in the series below? 2, 5, 10, 17, 26, 37, 50, 64
2014
Which number does not belong in the series below?
2, 5, 10, 17, 26, 37, 50, 64
- A.
17
- B.
37
- C.
64
- D.
26
Attempted by 144 students.
Show answer & explanation
Correct answer: C
Answer: 64 does not belong in the series.
Reason: The differences between consecutive terms form consecutive odd numbers.
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13
64 - 50 = 14 (this breaks the odd-number pattern)
Because the differences should be 3, 5, 7, 9, 11, 13, 15, the term after 50 should be 50 + 15 = 65. Therefore 64 is the incorrect term in the series; all other numbers follow the pattern.