TIMO 2021 Grade 4 Preliminary Set 2 Question 5

Find the missing number in the table below.

| First | Second | Third | Result |
|---:|---:|---:|---:|
| 2 | 5 | 1 | 11 |
| 3 | 6 | 2 | 20 |
| 4 | 7 | 3 | 31 |
| 5 | 8 | 4 | ? |