a. If a class B network uses a subnet mask 255.255.240.0, how many subnets are allowed? b. A large number of consecutive IP addresses are available starting at 128.16.0.0. Suppose that four organizations A,B,C and D request 2000, 1000, 2000, and 4000 addresses respectively, andin that order. For each of these, use the table below to give the first IP address assigned, the last IP address assigned, and the mask in the w. x. y. z /s notation and not /s. Include all 0s and all 1s in your allocation.

Organisation Starting Add Ending Add Adds allocated Mask