Least Common Multiple

Least Common Multiple

Definition of Least Common Multiple

Least common multiple is the smallest nonzero number that is a common multiple of two or more numbers considered.

More About Least Common Multiple

  • 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.

Video Examples: Least Common Multiple (LCM)

Example of Least Common Multiple

  • 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, . . .


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Solved Example on Least Common Multiple

Ques: Find the least common multiple of 13 and 11.

Choices:
  • A. 13
    B. 24
    C. 143
    D. 11
    Correct Answer: C

Solution:

  • 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.