Which number will replace the question mark(?) in the following series?
17, 37, 77, 157, 317, ?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 637.
Given series: 17, 37, 77, 157, 317, ?
The series follows the pattern:
17 + 20 = 37
37 + 40 = 77
77 + 80 = 157
157 + 160 = 317
317 + 320 = 637
So, the next term in the series is 637.