Tim rides his bike back and forth to work for each of his 5 workdays.  His work is 20 miles away.  He also goes for a weekend bike ride of 200 miles.    If he can bike at 25 mph how much time does he spend biking a week?
He bikes 20*2=<T>multiply(20, 2)=40 miles each day for work
So he bikes 40*5=<T>multiply(40, 5)=200 miles for work
That means he bikes a total of 200+200=<T>add(200, 200)=400 miles for work
So he bikes a total of 400/25=<T>divide(400, 25)=16.0 hours
