The GCD of given numbers is 3.
Step 1 : Place the numbers inside division bar:.
| 30 | 36 | 45 |
Step 2 : Divide numbers by 3.
| 3 | 30 | 36 | 45 |
| 10 | 12 | 15 |
Step 3 : Number 10, 12 and 15, cannot be divided any more. The GCD is:
$$ GCD = 3 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.