Least common multiple is the smallest nonzero number that is a common multiple of two or more numbers considered.
Finding LCM comes handy while adding, subtracting, or comparing two or more fractions with unlike denominators.
Least Common Denominator: Least common denominator is the least common multiple of the denominators of the fractions with unlike denominators.
The LCM of 6, 9, 15 is 90.
6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, . . .
9: 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, .
15: 15, 30, 45, 60, 75, 90, . . .
A. 13
B. 24
C. 143
D. 11
Correct Answer: C
Step 1: As 13 and 11 are coprimes, the least common multiple is nothing but their product.
Step 2: So, least common multiple of 13 and 11 is 143.
Q1: What is the LCM of 4 and 6?
Q2: What is the LCM of 5 and 7?
Q: How do you find the LCM?
A: List the multiples of each number until you find a common multiple. The smallest one is the LCM.
Q: What is the difference between LCM and GCF?
A: LCM is the smallest common multiple, while GCF is the largest common factor.