I believe that most of the answers to this lab are wrong.

e.g. Q5 to
15 = 00001111
so the first 20 bits are unchanged i.e. /20
The answer given is which would include for example
But the question is unclear because the CIDR notation is missing. without that this would be a Class A network and the IP addresses would both be on

Q6 - again CIDR is missing so say we assume class C
the first 17 bits are unchanged 120<128
So a good summary would be
The answer given which is only -

Q2 the question gives two /13 networks. the answer /16 how can that be a summary. I think works.

I could go on