How is user clock is synchronized with satellite clock to determine the transit time of the signal
AFAIK, the user time is treated as a free variable, like the user position. That's why at least four GPS satellites are needed. Or are you asking something else?
From time to time questions of this sort pop up on this forum, I have to say that even if I was capable of explaining these questions myself (which I am not), I wouldn't do so because you get the impression that you are being asked to complete a student's homework for them, however, in this case as Johnl has hinted at, the pseudorange (distance to) each satellite and the 'real' time is calculated simultaneously by using data from 4 or more satellites, the formulae are detailed in Bewitt's Basics of GPS, starting at page 13, I'm guessing that this is what the lecturer is asking the student to find
