The GCD of given numbers is 1.
Step 1 :
Divide $ 61 $ by $ 17 $ and get the remainder
The remainder is positive ($ 10 > 0 $), so we will continue with division.
Step 2 :
Divide $ 17 $ by $ \color{blue}{ 10 } $ and get the remainder
The remainder is still positive ($ 7 > 0 $), so we will continue with division.
Step 3 :
Divide $ 10 $ by $ \color{blue}{ 7 } $ and get the remainder
The remainder is still positive ($ 3 > 0 $), so we will continue with division.
Step 4 :
Divide $ 7 $ by $ \color{blue}{ 3 } $ and get the remainder
The remainder is still positive ($ 1 > 0 $), so we will continue with division.
Step 5 :
Divide $ 3 $ by $ \color{blue}{ 1 } $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 1 }} $.
We can summarize an algorithm into a following table.
61 | : | 17 | = | 3 | remainder ( 10 ) | ||||||||
17 | : | 10 | = | 1 | remainder ( 7 ) | ||||||||
10 | : | 7 | = | 1 | remainder ( 3 ) | ||||||||
7 | : | 3 | = | 2 | remainder ( 1 ) | ||||||||
3 | : | 1 | = | 3 | remainder ( 0 ) | ||||||||
GCD = 1 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.