Which of the following is the minimum value of the sum of two integers whose product is 36?
Answer: D
List all possible factors xx and yy whose product is 36, and calculate the corresponding sum x+yx+y:
| xx | yy | x×yx×y | x+yx+y |
| 1 | 36 | 36 | 37 |
| 2 | 18 | 36 | 20 |
| 3 | 12 | 36 | 15 |
| 4 | 9 | 36 | 13 |
| 5 | 6 | 36 | 12 |
From the table, the minimum sum is 12