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what is the common demonitors of 3/6 and 4/11

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2 Answers

the least common denominator is 66. 


for other problems multiply each denominator by the other like for this one you multiply 11 by 6 to get 66 

The least common denominator of two or more non-zero denominators is actually the smallest whole number that is divisible by each of the denominators.


There are two widely used methods for finding the least common denominator. Actually, this is the same basic idea behind finding the Least Common Multiple (LCM) for whole numbers (without the fractional parts).

Note: In the examples below, we’ll be adding three fractions instead of the usual two because the principles are the same. This will give you a better understanding of the process. Let’s take a look at…

Method 1: 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. Example: Suppose we wanted to add 1/5 + 1/6 + 1/15. We would find the least common denominator as follows…

•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.


Method 2: Easy method to find the common denominator is to multiply both the numbers in the denominator, and make it the common denominator.


If its an addition problem, Cross multiply the numerators with the denominator of the other number.

for example, 3/6 + 4/11= ?


the common denominator will be 6*11=66 the expression can be written as

3/6 + 4/11 = (3*11 +4*6)/66

                  =(33 + 24)/ 66



Hope this helps.