LCD means lowest (or least) common denominator, and that implies there must be at least two fractions involved for something to be common to both of them. There is, therefore, no sensible answer to this question.
60
120
20
LCD= 60
LCD(8, 20, 15) = 120
The least common denominator (LCD) is 1.
LCD(9, 15) = 45
LCD(15, 26) = 390
Pairs of number with the LCD of 5 are 5 and 10, 10 and 15, 20 and 25, and many more.
The LCD of 20 and 9 is 180.
LCD(12, 20) = 60
The LCD of 5 and 4 is 20.