Question

Find the GCD of $42$ and $24$ using Factor Tree.

• A. $1$
• B. $2$
• C. $3$
• D. $6$

Answer 1

The correct option is D $6$

Factor Tree is obtained by dividing the original number by its prime factors.

The Factor Tree of $42$ is as follows:


$\therefore 42=2\times 3\times 7$

And, the Factor Tree of $24$ is as follows:


$\therefore 24=2\times 2\times 2\times 3$

The common factors are $2$ and $3.$
$\therefore$ GCD $=2\times 3=6$