B類IP地址：子網位 /主機位 子網掩碼 子網最大數 /主機最大數2/14 255.255.192.0 2/16382 3/13 255.255.224.0 6/8190 4/12 255.255.240.0 14/4094 5/11 255.255.248.0 30/2046 6/10 255.255.252.0 62/1022 7/9 255.255.254.0 126/510 8/8 255.255.255.0 254/254 9/7 255.255.255.128 510/126 10/6 255.255.255.192 1022/62 11/5 255.255.255.224 2046/30 12/4 255.255.255.240 4094/14 13/3 255.255.255.248 8190/6 14/2 255.255.255.252 16382/2 C類IP地址：子網位 /主機位 子網掩碼 子網最大數 /主機最大數2/6 255.255.255.192 2/62 3/5 255.255.255.224 6/30 4/4 255.255.255.240 14/14 5/3 255.255.255.248 30/6 6/2 255.255.255.252 62/2

所以100臺電腦子網劃分是255.255.255.128 510/126

50臺電腦子網劃分是255.255.255.192 2/62

20臺電腦子網劃分255.255.255.224 6/30

10臺電腦子網劃分255.255.255.240 14/14