LCM for 42 and 105
What's the Least Common Multiple (LCM) of 42 and 105?
(Two hundred ten)
Finding LCM for 42 and 105 using GCF's of these numbers
The first method to find LCM for numbers 42 and 105 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:
LCM = (Number1 × Number2) ÷ GCF
GCF of numbers 42 and 105 is 21, so
LCM = (42 × 105) ÷ 21
LCM = 4410 ÷ 21
LCM = 210
Finding LCM for 42 and 105 by Listing Multiples
The second method to find LCM for numbers 42 and 105 is to list out the common multiples for both nubmers and pick the first which matching:
Multiples of 42: 42, 84, 126, 168, 210, 252, 294
Multiples of 105: 105, 210, 315, 420
So the LCM for 42 and 105 is 210
Finding LCM for 42 and 105 by Prime Factorization
Another method to find LCM for numbers 42 and 105 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors:
All Prime Factors of 42: 2, 3, 7 (exponent form: 21, 31, 71)
All Prime Factors of 105: 3, 5, 7 (exponent form: 31, 51, 71)
21 × 31 × 71 × 51 = 210
Related Calculations
See Also
- Greatest Common Factor - Find the Greatest Common Factor (GCF) of two numbers
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