1)
215.83.25.0 => 255.255.255.X
6 ~= 2^3 => 3 bits de máscara subred => 8 - 3 = 5 bits de host

Máscara global de red: 2^7 + 2^6 + 2^5 = 224 => 255.255.255.224

Número de hosts: 2^5 - 2 = 30

Dir. Subred                      | Dir. Bcast    | Rango IPs
---------------------------------|---------------|------------------
000 00000 = 0   => 215.83.25.0   | 215.83.25.31  | 215.83.25.1-30
001 00000 = 32  => 215.83.25.32  | 215.83.25.63  | 215.83.25.33-62
010 00000 = 64  => 215.83.25.64  | 215.83.25.95  | 215.83.25.65-94
011 00000 = 96  => 215.83.25.96  | 215.83.25.127 | 215.83.25.97-126
100 00000 = 128 => 215.83.25.128 | 215.83.25.159 | 215.83.25.129-158
101 00000 = 160 => 215.83.25.160 | 215.83.25.191 | 215.83.25.161-190

2)
116.0.0.0 => 255.X.X.X
15 ~= 2^4 => 4 bits de máscara subred => 24 - 4 = 20 bits de host

Máscara global de red: 255.240.0.0

Número de hosts: 2^20 - 2 = 1 048 574

Dir. Subred                    | Dir. Bcast      | Rango IPs
-------------------------------|-----------------|------------------------------
0000 0000 = 0   => 116.0.0.0   | 116.15.255.255  | 116.0.0.1 - 116.15.255.254
0001 0000 = 16  => 116.16.0.0  | 116.31.255.255  | 116.16.0.1 - 116.31.255.254
0010 0000 = 32  => 116.32.0.0  | 116.47.255.255  | 116.32.0.1 - 116.47.255.254
0011 0000 = 48  => 116.48.0.0  | 116.63.255.255  | 116.48.0.1 - 116.63.255.254
0100 0000 = 64  => 116.64.0.0  | 116.79.255.255  | 116.64.0.1 - 116.79.255.254
0101 0000 = 80  => 116.80.0.0  | 116.95.255.255  | 116.80.0.1 - 116.95.255.254
0110 0000 = 96  => 116.96.0.0  | 116.111.255.255 | 116.96.0.1 - 116.111.255.254
0111 0000 = 112 => 116.112.0.0 | 116.127.255.255 | 116.112.0.1 - 116.127.255.254
1000 0000 = 128 => 116.128.0.0 | 116.143.255.255 | 116.128.0.1 - 116.143.255.254
1001 0000 = 144 => 116.144.0.0 | 116.159.255.255 | 116.144.0.1 - 116.159.255.254
1010 0000 = 160 => 116.160.0.0 | 116.175.255.255 | 116.160.0.1 - 116.175.255.254
1011 0000 = 176 => 116.176.0.0 | 116.191.255.255 | 116.176.0.1 - 116.191.255.254
1100 0000 = 192 => 116.192.0.0 | 116.207.255.255 | 116.192.0.1 - 116.207.255.254
1101 0000 = 208 => 116.208.0.0 | 116.223.255.255 | 116.208.0.1 - 116.223.255.254
1110 0000 = 224 => 116.224.0.0 | 116.239.255.255 | 116.224.0.1 - 116.239.255.254

3)
183.24.0.0 => 255.255.X.X
10 ~= 2^4 => 4 bits de máscara subred => 16 - 4 = 12 bits de host

Máscara global de red: 255.255.240.0
Número de hosts: 2^12 - 2 = 4094

Dir. Subred                     | Dir. Bcast      | Rango IPs
--------------------------------|-----------------|------------------------------
0000 0000 = 0   => 183.24.0.0   | 183.24.15.255   | 183.24.0.1 - 183.24.15.254
0001 0000 = 16  => 183.24.16.0  | 183.24.31.255   | 183.24.16.1 - 183.24.31.254
0010 0000 = 32  => 183.24.32.0  | 183.24.47.255   | 183.24.32.1 - 183.24.47.254
0011 0000 = 48  => 183.24.48.0  | 183.24.63.255   | 183.24.48.1 - 183.24.63.254
0100 0000 = 64  => 183.24.64.0  | 183.24.79.255   | 183.24.64.1 - 183.24.79.254
0101 0000 = 80  => 183.24.80.0  | 183.24.95.255   | 183.24.80.1 - 183.24.95.254
0110 0000 = 96  => 183.24.96.0  | 183.24.111.255  | 183.24.96.1 - 183.24.111.254
0111 0000 = 112 => 183.24.112.0 | 183.24.127.255  | 183.24.112.1 - 183.24.127.254
1000 0000 = 128 => 183.24.128.0 | 183.24.143.255  | 183.24.128.1 - 183.24.143.254
1001 0000 = 144 => 183.24.144.0 | 183.24.159.255  | 183.24.144.1 - 183.24.159.254