Question

Find the LCM of the following integers by applying the prime factorization method
12, 15 and 21

• A. $420$
• B. $419$
• C. $430$
• D. $450$

Answer 1

The correct option is A $420$

$12=2\times 2\times 3$
$15=3\times 5$
$21=3\times 7$

$LCM=2\times 2\times 3\times 5\times 7=420$