1-A teacher started his class at 7:00 and 15 min and finished at 8:50 a. m. How many minutes did class last? 2-Doing physical exercises for 50 min per day for 20 days, how many hours will be spent per month to do these exercises?

3-In a school each class lasts 50 minutes and each class has 5 lessons per day. Knowing that there is a 30-minute break, calculate how many hours students spend per day at this school.

help me please