Answer:
20 minutes
Step-by-step explanation:
70 minute classes times 3
Plus 2 breaks one in between 1st and 2nd class
And another in between 2nd and 3rd class
Which = 220 minutes
4 hours times 60 (because 60 minutes per hour)
Gives us 240 minutes
Then you subtract total time from time in classes and breaks
Which gives us 20 minutes for lunch time