A common denominator is 72.
72
The Greatest Common Denominator is 6
For 18 and 56: 504 For 1/8 and 5/6 : 24
The LCD of 1/3 and 1/8 is 24.
If those are all denominators, the LCD is 360.
Multiply 4 to 18, and 3 to 24. You get a denominator of 72
First a common denominator must be found. The denominators are 2,3,4,8. 24 is the Lowest Common Denominator. Now convert all the fractions with 24 as the denominator. ⅓=8/24 ⅛=3/24 ½=12/24 ⅜=9/24 ⅞=21/24 ⅔=16/24 ¼=6/24 ⅝=15/24 ¾=18/24 ½ =12/24 The denominator will be 24. Add the numerators. 8+3+12+9+21+16+6+15+18+12 =120 The fraction is 120/24 which is equal to 5.
A common denominator, though not the least one, is 24*21 = 504.
A common denominator, though not the least one, is 16*24 = 384.
The lowest common multiple, or lowest common denominator, of 18 and 28 is 252.
The common denominator is usually the Lowest (or Least) Common Multiple of the numbers involved. Where two numbers have no common factors then the LCM is simply the product of those numbers. As 19 is a prime number and has no factors in common with 18 then the common denominator is 18 x 19 = 342.
The greatest common denominator is infinite.