Best Answer

To find both of these you first need to break up the numbers into their prime factors:

18 = 2x3x3

20 = 2x2x5

Th next step is to identify any common prime factors. The only common prime factor between these two is a single 2. The GCF is therefore 2. The LCM is every other factor multiplied together:

3x3x2x2x5=180, so the LCM of 18 and 20 is 180.

User Avatar

Wiki User

12y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What is the gcf and LCM of 18 and 20?
Write your answer...
Still have questions?
magnify glass