So the numbers you have are 20, 15 and 8
The Greatest Common Factor (GCF) is well... is the name itself
We do the prime factorization of the numbers:
[tex]20=2^2*5 \\ 15=3*5 \\ 8= 2^{3} [/tex]
The GCF is 1 since the three don't have a common factor.
The LCM is computed by getting the greatest power of 2 from the given, greatest power of 3, etc. and multiplying them.
The greatest power of 2 is 3 so [tex]2^3[/tex]
The greatest power of 3 is 1 so [tex]3[/tex]
And the greatest power of 5 is 1 so [tex]5[/tex]
[tex]LCM=2^3*3*5=8*3*5=120[/tex]
The LCM is 120
