How many sockets do Google open for every request it receives?

Question

The following is my recent interview experience with a reputed network software company. I was asked questions about interconnecting TCP level and web requests and that confused

Answer 1

For point #6, here is how I understand it: if both ends of an end to end connection were the same as that of another socket, there would indeed be no way to distinguish both socket, but if a single end is not the same as that of the other socket, then it's easy to distinguish both. So there is not need to turn destination port 80 (the default) forth and back, since the source ports differ.