Diana needs to bike 10 miles to get home. She can bike 3 mph for two hours before she gets tired, and she can bike 1 mph until she gets home. How long will it take Diana to get home? Think carefully first, then make a decision:
In the first part of her trip, Diana will cover 2 hours * 3 mph = 6 miles. In the second part of her trip, Diana will need to cover an additional 10 miles - 6 miles = 4 miles. To cover 4 miles * 1 mph = will take Diana 4 hours. Total biking time to get home for Diana will be 2 hours + 4 hours = 6 hours. So, the answer is 6.