Answer: 19 miles
Step-by-step explanation:
Distance = speed × time
Biking at 10 mph, it takes Kristen 1/2 hour to reach the train station to go to work. This means that the distance covered on her way to the train station is
0.5 × 10 = 5 miles
Kristen then takes the train to work, and it takes another 1/2 hour for her to get to work when the train travels 28 mph. Distance covered by the train is
0.5 × 28 = 14 miles
Therefore, the distance that Kristen travels to work is
14 + 5 = 19 miles
