The GCD of given numbers is 1.
Step 1 : Find prime factorization of each number.
$$\begin{aligned}1 =& 1~~~ \color{gray}{\text{ (1 is prime)}} \\[8pt]1 =& 1~~~ \color{gray}{\text{ (1 is prime)}} \\[8pt]\end{aligned}$$(view steps on how to factor 1 and 1. )
Step 2 : Put a box around factors that are common for all numbers:
$$\begin{aligned}1 =& \color{blue}{\boxed{1}}\\[8pt]1 =& \color{blue}{\boxed{1}}\\[8pt]\end{aligned}$$Step 3 : Multiply the boxed numbers together:
$$ GCD = 1 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.