The GCD of given numbers is 4.
Step 1 :
Divide $ 124 $ by $ 108 $ and get the remainder
The remainder is positive ($ 16 > 0 $), so we will continue with division.
Step 2 :
Divide $ 108 $ by $ \color{blue}{ 16 } $ and get the remainder
The remainder is still positive ($ 12 > 0 $), so we will continue with division.
Step 3 :
Divide $ 16 $ by $ \color{blue}{ 12 } $ and get the remainder
The remainder is still positive ($ 4 > 0 $), so we will continue with division.
Step 4 :
Divide $ 12 $ by $ \color{blue}{ 4 } $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 4 }} $.
We can summarize an algorithm into a following table.
124 | : | 108 | = | 1 | remainder ( 16 ) | ||||||
108 | : | 16 | = | 6 | remainder ( 12 ) | ||||||
16 | : | 12 | = | 1 | remainder ( 4 ) | ||||||
12 | : | 4 | = | 3 | remainder ( 0 ) | ||||||
GCD = 4 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.