code:

Your boss forgot to send you the email about the new site 
scheduled to be brought up in 1 hour.  It must have enough 
IP addresses to support the current 10 people, printers, 
and network equipment, plus have room to grow to 30.  
Which of the following IP addresses would satisfy the 
requirements?

A. 10.192.168.64/29
B. 192.168.10.64/27
C. 172.16.10.64/28
D. 10.172.31.0/28

code:

Given the following IP address and mask, provide the class,
network ID, # subnets, and # of hosts per net:


Address/mask        Class  Net ID              #subs    # hosts
==================  =====  ==================  =======  ========
___.___.___.___/__    _    ___.___.___.___/__  _______  ________

127.136.42.21/24      Illegal address (reserved for loopbacks)

224.4.102.3/24        D     N/A                    N/A       N/A

4.192.255.61/27       A    4.192.255.32/27      524286        30

Net    4.192.255. 61
Mask 255.255.255.224

       4.1100 0000.1111 1111.0001 1100
     255.1111 1111.1111 1111.1110 0000
        |     SN               |----   <--subnets
                     ----------| H   | <--hosts 

142.240.98.206/29     B    142.240.98.200/29      8190         6

     142.240.0110 0010.1100 1110
     255.255.1111 1111.1111 1000
          --|   SN          |--   <--subnets
                     -------|H  | <--hosts 

Did I catch you on the 127 address?