lets add together breaks and all day long:
all day: from 8:50 to 15:15: that is 6 hours and 25 minutes, that is in minutes:
all day = 6*60 + 25 = 385 minutes
breaks:
play: 10:40 to 10:55: that is 15 minutes
lunch: 12:00 to 1:05: that is one hour and 5 minutes, or 65 minutes
breaks = 15 + 65 = 80 minutes
So the school day of work is: 385 - 80 = 305 minutes
That is 5 hours and 5 minutes
Remember, an hour is 60 mins.
