
Least Common Multiple (LCM) of 20 and 42
The least common multiple (LCM) of 20 and 42 is 420.
What is the Least Common Multiple (LCM)?
The LCM of two integers is the smallest positive integer that is divisible by both numbers. It is often used to find common denominators and solve problems involving periodic events.
Formula for LCM
The LCM of two numbers can be calculated using their GCD:
LCM(a, b) = |a × b| ÷ GCD(a, b)
How to Calculate the LCM of 20 and 42?
First, calculate the GCD of 20 and 42 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
Step | Calculation |
---|---|
1 | 20 ÷ 42 = 0 remainder 20 |
2 | 42 ÷ 20 = 2 remainder 2 |
3 | 20 ÷ 2 = 10 remainder 0 |
Examples of LCM Calculations
Numbers | LCM |
---|---|
52 and 48 | 624 |
134 and 23 | 3082 |
67 and 193 | 12931 |
121 and 124 | 15004 |
193 and 155 | 29915 |