Hi I need help for these question for computers networking question

You are asked to set up a virtual meeting, using speaker phones to create a conference call that will allow a group often people at ten different sites to have an important meeting. Which will most closely fit your needs, unicast, multicast, or broadcast? Why? A single telephone conversation has a bandwidth of 3000Hz. If a major telephone trunk can handle a total of 10MHz of frequency, how many telephone conversations can fit on this line? Assume you will allow a total of 1000Hz of "buffer" between conversations to prevent interference. Did you perform this calculation using FDM, STDM, or statistical multiplexing? You are transmitting a 10MB file from one end of the country to the other over a 100Mbps link. Is this transmission dominated by bandwidth concerns, latency concerns, or a combination of both? Assume the transcontinental latency is 0.024 seconds