Correct Answer - Option 2 : 31
Given:
18, 19, 23, 31, 48, 73
Calculation:
The series follows the following pattern,
18 + 12 = 19
19 + 22 = 23
23 + 32 = 32 ≠ 31
32 + 42 = 48
48 + 52 = 73
Since 32 will come in place of 31.
∴ The required wrong number will be 31.