The multiples of 6 and 24 are infinite, so there is no greatest common multiple for them or any set of numbers.
The answer is 6
GCM(18, 42) = 6
GCF: 12 LCM: 72 GCM: infinite
24
8
If GCM stands for Greatest Common Multiple, there is no such number. This is because if x is claimed as the GCM then 2x is a common multiple of both 6 and 8 and 2x > x.
12
2.
LCM: 54 GCD: 6
Density = Mass/Volume = 112/24 gcm-3 = 4.667 gcm-3
It is infinite but the lowest common multiple is 72
192.