Need some help please, not sure how to begin this problem?

A train leaves Colorado Springs at 9 a.m. bound for Boulder, Colo., 100 miles away. It travels at 50 mph and has to pick up pengers every 25 miles. Each stop takes 10 minutes, and after each stop, the increased penger weight causes the train's speed to decrease by 10 percent, what tim e will it reach it's destination?