have a class B network and want to divide it into subnets, each with 126 hosts, which subnet mask should you use? How many networks will be available?...

If you have a class B network and want to divide it into subnets, each with 126 hosts, which subnet mask should you use? How many networks will be available? What are the four addresses (broadcast and network number) for the network starting at 131.204.18?