The GCD of given numbers is 9.
Step 1 : Place the numbers inside division bar:.
| 702 | 153 | 405 |
Step 2 : Divide numbers by 3.
| 3 | 702 | 153 | 405 |
| 234 | 51 | 135 |
Step 3 : Divide numbers by 3.
| 3 | 702 | 153 | 405 |
| 3 | 234 | 51 | 135 |
| 78 | 17 | 45 |
Step 4 : Number 78, 17 and 45, cannot be divided any more. The GCD is:
$$ GCD = 3\cdot3 = 9 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.