A> How is a Class C address of to be masked.
A> If 20 subnets with 5 hosts per subnet are required

"Let me see now. The train leaving Paris is travelling at 150 km/h. The
second train left Rome at 19:05. ... Erm ... Multiply by 3600 ... The
distance between the trains 2 minutes before the tunnel accident is ...
Therefore ... Carry the 9 ..."

"Miss! Wasn't this examination supposed to be multiple-choice?"