If 16-port Ethernet switches are used to upgrade a network, that has 80 computers, 5 servers, 10 network ready Laser printers, & a hardware firewall & wireless access points, as well as anti-virus software on the computers & servers, how many would be needed? Also the printers shouldn't be all connected to one switch, instead distributed so that one is available for every 8 computers.
Um... number of total devices divided by 16. Yay for math! Maybe a few extra due to the printers per switch requirement but that's a bit false as having a printer on a different switch from a PC will not stop that PC from connecting to it, so there is no need to have a printer per switch per 8 PCs unless they are all in their own subnets.
And don't play on your iphone in class when you should be listening.