This cannot be answered properly because at least two numbers are required.
The least common denominator for 9 and 10 is 90.
360
4410
It is: 90
It is: 1080
It is: 90
LCD(30, 45) = 90
You need at least two numbers to find something in common. 90 can be a common denominator of other numbers, but it can't have a common denominator all by itself.
That's the least common denominator or LCD.
The least common denominator.
The LCD of 18 and 30 is 90
The LCM of these three numbers is 90.