I have seen this question being asked before but the answers are incomplete. Does anyone know the correct and complete answer?

Consider a voice-over-IP system that transmits 64Kbits/s PCM voice using RTP/UDP/IP with a packetization interval of 20ms. How many such streams can be transmitted over a 10Mbps Ethernet link assuming the link can be loaded up to 80%? What is the maximum number of streams if packetization interval of 10ms was used? If these streams with a packetization interval of 20ms were transmitted to a mobile user using Mobile IP, what is the maximum number of streams over the same link when using a) IP in IP encapsulation, b) minimum encapsulation, and c) GRE encapsulation? Assume no options are enabled.