RRB NTPC · Question 65
Insert the missing character marked as ‘?’.
| 1 | 2 | 3 |
|---|---|---|
| 11 | 7 | 5 |
| 120 | 45 | ? |
Show answer & explanation
Answer: (C) 16
Explanation
Each bottom number is the square of the middle number minus the square of the top: 11² − 1² = 120 and 7² − 2² = 45. So ? = 5² − 3² = 25 − 9 = 16.