The GCD of given numbers is 35.
Step 1 :
Divide $ 385 $ by $ 210 $ and get the remainder
The remainder is positive ($ 175 > 0 $), so we will continue with division.
Step 2 :
Divide $ 210 $ by $ \color{blue}{ 175 } $ and get the remainder
The remainder is still positive ($ 35 > 0 $), so we will continue with division.
Step 3 :
Divide $ 175 $ by $ \color{blue}{ 35 } $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 35 }} $.
We can summarize an algorithm into a following table.
385 | : | 210 | = | 1 | remainder ( 175 ) | ||||
210 | : | 175 | = | 1 | remainder ( 35 ) | ||||
175 | : | 35 | = | 5 | remainder ( 0 ) | ||||
GCD = 35 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.