How to calculate the addresses
Going on the assumption that there is already a given network, in this case 192.168.1.0/24, we need to figure out how to subnet it. We do this by using something like Microsoft Excel or Google Spreadsheets. After deciding how many hosts are needed for each subnet, in this case we need 5 separate networks at the very least with 30 hosts between them, so we need a CIDR(Classless Inter-Domain Routing) of /27. This admittedly divides the 255 available hosts into 8 different networks of 32 hosts but it's fine cause we don't have to use them all. Now onto the actual calculating, we know the network is 192.168.1.0, so the first subnet for Foster shall start there. Due to the rules of IP networking, the first address can't be the first usable address, that means the first usable address for a subnet is always the first address + 1. Since the subnets are divided into 32 hosts, the next network starts on 32, therefore the last possible address of the first network is 31. Once again in the case of networking, the last possible address of a network has to be the broadcast address, so 31 is the broadcast address of subnet 1, and therefore the last usable address of the network is the broadcast address minus 1, in this case 30. Now we have the first subnet completed, with it beginning at 192.168.1.0, the first usable address being 192.168.1.1, the last usable address 192.168.1.30, and the broadcast address is 192.168.1.31. Now the rest of the networks are easy to find, they are simply the previous all of previous subnets +32. So the next subnet of Joyce, begins at 192.168.1.32, the first usable address at 192.168.1.33, the last usable at 192.168.1.62, and a broadcast of 192.168.1.63. This repeats for every subnet until we get to our final needed network at the fifth subnet ending at the last possible address of 192.168.1.159. See the attached screenshot of the spreadsheet to see the necessary calculation sheet.
