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? Let's answer step by step:
He bikes 20 * 2 = 40 miles each day for work. So he bikes 40 * 5 = 200 miles for work. That means he bikes a total of 200 + 200 = 400 miles for work. So he bikes a total of 400 / 25 = 16 hours. The answer: 16.