Find the next term of the following number series – 5, 24, 61, 122, 213, 340, ?
2022
Find the next term of the following number series – 5, 24, 61, 122, 213, 340, ?
- A.
468
- B.
509
- C.
528
- D.
614
Attempted by 60 students.
Show answer & explanation
Correct answer: B
Analysis of the Series
The series follows a pattern based on cubes minus 3, or a consistent second-level difference:
Pattern 1 (Cubes - 3):
2³ - 3 = 8 - 3 = 5
3³ - 3 = 27 - 3 = 24
4³ - 3 = 64 - 3 = 61
5³ - 3 = 125 - 3 = 122
6³ - 3 = 216 - 3 = 213
7³ - 3 = 343 - 3 = 340
8³ - 3 = 512 - 3 = 509
Pattern 2 (Difference Method):
The differences between terms are: 19, 37, 61, 91, 127.
The differences of those differences are: 18, 24, 30, 36.
The next difference is 36 + 6 = 42.
The next term in the series is 340 + (127 + 42) = 340 + 169 = 509.