It is: 600
The LCM is: 600
The multiples of 20 are: 20, 40, 60, 80, 100, 120, 140, etc ...The multiples of 30 are: 30, 60, 90, 120, 150, etc ...The multiples of 40 are: 40, 80, 120, 160, etc. ...The lowest multiple common to 20, 30, and 40 is 120, so the LCM = 120
The LCM is 150.
The LCM would be 150 !
The LCM is 4950.
The LCM is 3300.
The LCM is 600.
The LCM is 450.
The LCM is 300.
The LCM is 600.
The LCM is 150.
The LCM is 750.