The LCM is 816.
For 816 and 20, it's 4080. For 8, 16 and 20 it's 80.
LCM: 816
816
816
LCM(68, 48) = 816
gcf(16, 51) = 1 lcm(16, 51) = 816
If that's 12, 48 and 16, the LCM is 48. If that's 124 and 816, the LCM is 25296.
The LCM of 20 and 20 is 20.
The LCM is 20.
The LCM is: 20
20