LCM for 18 and 15
What's the Least Common Multiple (LCM) of 18 and 15?
(Ninety)
Finding LCM for 18 and 15 using GCF's of these numbers
The first method to find LCM for numbers 18 and 15 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 18 and 15 is 3, so
LCM = (18 × 15) ÷ 3
LCM = 270 ÷ 3
LCM = 90
Finding LCM for 18 and 15 by Listing Multiples
The second method to find LCM for numbers 18 and 15 is to list out the common multiples for both nubmers and pick the first which matching:
Multiples of 18: 18, 36, 54, 72, 90, 108, 126
Multiples of 15: 15, 30, 45, 60, 75, 90, 105, 120
So the LCM for 18 and 15 is 90
Finding LCM for 18 and 15 by Prime Factorization
Another method to find LCM for numbers 18 and 15 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:
All Prime Factors of 18: 2, 3, 3 (exponent form: 21, 32)
All Prime Factors of 15: 3, 5 (exponent form: 31, 51)
21 × 32 × 51 = 90
Related Calculations
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