Hi, struggling with computer networks questions much help would be greatly appreciated

- if using 16 bits for the network part of a class B address, 20 bits have been used. How many class B networks would there have been?

- class B network on the internet has a subnet mask of 255.255.240.0, what is the maximum number of host per subnet?

-arp & rarp both map addresses from one space to another, in this respect, they are similar. however their implementations are fundamentally different, in what major way do they differ?