Answer:
In mathematics, the lowest common denominator or least common denominator (abbreviated LCD) is the lowest common multiple of the denominators of a set of fractions. It simplifies adding, subtracting, and comparing fractions.
How to find/solve LCD?
To find the least common denominator, simply list the multiples of each denominator (multiply by 2, 3, 4, etc. out to about 6 or seven usually works) then look for the smallest number that appears in each list.
•First we list the multiples of each denominator.
Multiples of 5 are 10, 15, 20, 25, 30, 35, 40,…
Multiples of 6 are 12, 18, 24, 30, 36, 42, 48,…
Multiples of 15 are 30, 45, 60, 75, 90,….
•Now, when you look at the list of multiples, you can see that 30 is the smallest number that appears in each list.
•Therefore, the least common denominator of 1/5, 1/6 and 1/15 is 30.
This method works pretty good. But, adding fractions with larger numbers in the denominators it can get pretty messy.
