Find Greatest Common Divisor of 93 and 42, using Euclidean algorithm.
Answer
The GCD of given numbers is 3.
Explanation
Step 1 :
Divide $ 93 $ by $ 42 $ and get the remainder
The remainder is positive ($ 9 > 0 $), so we will continue with division.
Step 2 :
Divide $ 42 $ by $ \color{blue}{ 9 } $ and get the remainder
The remainder is still positive ($ 6 > 0 $), so we will continue with division.
Step 3 :
Divide $ 9 $ by $ \color{blue}{ 6 } $ and get the remainder
The remainder is still positive ($ 3 > 0 $), so we will continue with division.
Step 4 :
Divide $ 6 $ by $ \color{blue}{ 3 } $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 3 }} $.
We can summarize an algorithm into a following table.
| 93 | : | 42 | = | 2 | remainder ( 9 ) | ||||||
| 42 | : | 9 | = | 4 | remainder ( 6 ) | ||||||
| 9 | : | 6 | = | 1 | remainder ( 3 ) | ||||||
| 6 | : | 3 | = | 2 | remainder ( 0 ) | ||||||
| GCD = 3 | |||||||||||
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.