There are 2^(232 − 24) = 256 addresses in this block. The first address is 208.10.128.0/24; the last address is 14.24.74.255/24
[A] ECE :The number of addresses in the second subblock is not a power of 2 either. We allocate 64 addresses.The subnet mask is 26. The first address in this block is 208.10.128.0/26; the last address is 208.10.128.59/26
[B] CSE :The number of addresses in the first subblock is not a power of 2. We allocate 128 addresses.The subnet mask is 25.The first address is 208.10.128.60/25; the last address is 208.10.128.179/25
[C] EEE : First address 208.10.128.180/27 the last address 208.10.128.209/27
[D] MEC :First address 208.10.128.210/27 the last address 208.10.128.239/27