Eman skateboarded 24 miles in 2 hours on Monday and 6 miles in a half hour. He noticed the total distance he is skateboarding is proportional to the time he skateboards. Hiro has been tracking his speed while riding his bike. He noticed that he can bike 15 miles per hour. If Eman and Hiro left school to go to the park and traveled the same route, who would take longer to get to the park if they maintain their average rates?