What is the LCM of 18 and 21?
The Least Common Multiple is also referred to as the Lowest Common Multiple ( LCM ) and Least Common Divisor ( LCD) . For two integers a and b, denoted LCM(a,b), the LCM is the smallest positive integer that is evenly divisible by both a and b.
Answer: LCM of 18 and 21 is 126
We can calculate LCM using various methods such as
LCM of 18 and 21 by Listing Method
In this method the first few multiples of 18 and 21 are listed below and the lowest common multiple is chosen
LCM of 18 and 21 by Formula
The formula of LCM is LCM (a, b) = (a × b) / GCF (a, b)
The Greatest Common Factor of (18, 21) = 3
By substituting we get,
LCM of 18 and 21 = (18 × 21) / 3
LCM of 18 and 21 = 126