Consider the following non-default subnet masks:

(a) 255.255.248.0,

(b) 255.128.0.0 . To which IP address class do they pertain? Write down the following in CIDR notation:

(a) IP: 150.160.170.180, Subnet Mask: 255.255.224.0;

(b) IP: 75.80.85.90, Subnet Mask: 255.252.0.0

Three stations A, B, C and D are connected to a common Ethernet hub. Their IP addresses and subnet mask are respectively: 200.100.50.67, 255.255.255.252; 200.100.50.7, 255.255.255.248; 200.100.50.138, 255.255.255.240 and 200.100.50.1, 255.255.255.254. Determine which among these stations can communicate with each other.

You need to show all detailed workings.