3:15; 6:00!
What nonsense. No instructor with even the most brilliant student can cover all the necessary air exercises in that short time. After the upper air exercises, it then takes at least two hours of uninterrupted circuit training to achieve the requisite "three unassisted circuits and landings" required for a first solo!
Any Flying Instructor sending a student solo in less than 10 hours should be seriosly examined by the CFI. (That's Chief Flying Instructor for the cousins.)