Find the least common multiple (LCM) of the numbers 20, 18.
A) 1
B) 2
C) 360
D) 180
E) 20

Question

Quizplus · Accepted Answer

To find the LCM, we need to list the multiples of each number and find the smallest one they have in common. 
Multiples of 20: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300...
Multiples of 18: 18, 36, 54, 72, 90, 108, 126, 144, 162, 180, 198, 216, 234, 252, 270...
The smallest multiple that both have in common is 180, so the LCM of 20 and 18 is 180. Option D is correct.

Find the Least Common Multiple (LCM) of the Numbers 20