255.255.252.0 is true
There are 16 bits available; it is up to you how many of those bits you reserve for the subnet, and how many for the individual hosts within each subnet.
yes
255.255.252.0
255.255.252.0
You have given a subnet mask; it has nothing to do with hosts. You would need to supply the network number.
172.16.4.255
172.16.4.225
No, changing the prefix of a subnet will affect the number of hosts that can be assigned. A smaller prefix will result in fewer hosts, while a larger prefix will allow for more hosts to be assigned.
A network with an IP address 192.168.1.1 is a class C IPv4 network address in the network 192.168.1.0 with a subnet mask 255.255.255.0, capable of supporting 253 hosts.
Depending on the subnet masks, these hosts may or may not be able to directly communicate.
255.255.254.0