Mascara de Rede: 11111111.11111111.11111111.11100000
Quantidade de sub-redes: 2^3 = 8
Quantidade de host: 2^5 - 2 = 30
Faixas de de cada sub-rede
Sub-rede 1
Rede: 221.215.237.0
Host: 221.215.237.1 até 221.215.237.30
Broadcast: 221.215.237.31
Sub-rede 2
Rede: 221.215.237.32
Host: 221.215.237.33 até 221.215.237.62
Broadcast: 221.215.237.63
Sub-rede 3
Rede: 221.215.237.64
Host: 221.215.237.65 até 221.215.237.94
Broadcast: 221.215.237.95
Sub-rede 4
Rede: 221.215.237.96
Host: 221.215.237.97 até 221.215.237.126
Broadcast: 221.215.237.127
Sub-rede 5
Rede: 221.215.237.128
Host: 221.215.237.129 até 221.215.237.158
Broadcast: 221.215.237.159
Sub-rede 6
Rede: 221.215.237.160
Host: 221.215.237.161 até 221.215.237.190
Broadcast: 221.215.237.191
Sub-rede 7
Rede: 221.215.237.192
Host: 221.215.237.193 até 221.215.237.222
Broadcast: 221.215.237.223
Alternativa: B