For each of these IP addresses fill in the entries. assume classful addressing and default subnet masks.
class default mask prefix network address registered or unregistered? broadcast address range of host addresses #hosts
192.168.100.102
192.168.0.1
111.111.111.111
222.222.222.222
1.2.3.4
192.168.50.73
172.18.0.5
10.0.0.1

here, the "class" is based/indicated by the subnet mask. Actually, "class" only means the size of the network.
class subnet mask prefix network address registered or unregistered? broadcast address range of host addresses #hosts
10.10.19.47 255.255.255.0
172.16.0.1 255.255.255.0