Depends on the time of year, for the first two months maybe 8-9 hours a day (4-5 of those hours would be at school), then I did probably like 7-8 hours a day (4-5 of those at school) until Feburary, then from February half-term till the end like 10-12 hours a day, consistently 12 hours from April.
Ended with A*A*A* in Maths, f. Maths and physics. And B in my fourth A-level of chemistry but that didn't really mean anything.