Question

A school day lasts from 9:00am to 3:45

Answer 1

9:00 to 3:45 = 6 hours 45 min
1 lesson = 55 min
6 lessons = 5 hours 30 min 
5.3 + 0.25 = 5 hours 55 min
6.45 - 5.55 = 50 min
lunch = 50 min