Which number will replace the question mark (?) in the following series?
17, 19, 24, 34, 51,?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1, i.e., 77.
19 - 17 = 2, 24 - 19 = 5, 34 - 24 = 10, 51 - 34 = 17.
The differences between these differences are: 5 - 2 = 3, 10 - 5 = 5, and 17 - 10 = 7.
The second differences are consecutive odd numbers (3, 5, 7). Therefore, the next difference should be 9. So, 17 + 9 = 26. The next term in the series is 51 + 26 = 77.