LCM for 7 and 20
What's the Least Common Multiple (LCM) of 7 and 20?
(One hundred forty)
Finding LCM for 7 and 20 using GCF's of these numbers
The first method to find LCM for numbers 7 and 20 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 7 and 20 is 1, so
LCM = (7 × 20) ÷ 1
LCM = 140 ÷ 1
LCM = 140
Finding LCM for 7 and 20 by Listing Multiples
The second method to find LCM for numbers 7 and 20 is to list out the common multiples for both nubmers and pick the first which matching:
Multiples of 7: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133, 140, 147, 154
Multiples of 20: 20, 40, 60, 80, 100, 120, 140, 160, 180
So the LCM for 7 and 20 is 140
Finding LCM for 7 and 20 by Prime Factorization
Another method to find LCM for numbers 7 and 20 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:
All Prime Factors of 7: 7 (exponent form: 71)
All Prime Factors of 20: 2, 2, 5 (exponent form: 22, 51)
71 × 22 × 51 = 140
Related Calculations
See Also
- Greatest Common Factor - Find the Greatest Common Factor (GCF) of two numbers
<a href="https://calculat.io/en/number/least-common-multiple-lcm-of/7--20">What is the LCM of 7 and 20? - Calculatio</a>
LCM Table
About "Least Common Multiple" Calculator
Least Common Multiple (LCM) also known as the Lowest Common Multiple or Smallest Common Multiple of 2 numbers - it is the smallest positive integer that is divisible by both numbers