It took me 2 hours and 30 minutes but I have to say that I was only 16 years old so you learn faster and I had done some glider flying.
On the other hand, I know one guy that recently needed 100 hours before getting solo.
In the Air Force where I instruct, the students get 10 hours of circuit training to get solo, if they fail they get 2 extra hours, if they fail that they are out. But before starting the circuit work they get 12 hours of general flying (SLF, climb, climb, descend, turns, stall clean, stal landing configuration, SLF in other configuration, range endurance, emergency descend, steep turns)
Bart