The distance from City A to City B is 150 miles. While driving from City A to City B, Cara drives at a constant speed of 30 miles per hour. Dan leaves City A 90 minutes after Cara. What is the minimum constant speed in miles per hour that Dan must exceed in order to arrive in City B before Cara?
Select the correct option
A) 42.85  B) 44  C) 46  D) 48  E) 50
The time it takes Cara to drive to City B is 150 / 30= 
<gadget id="calculator">150 / 30</gadget>
<output>5</output>
5 hours.   Dan needs to take less than 3.5 hours for the trip.   Dan needs to exceed a constant speed of 150 / 3.5= 42.85 miles per hour.   The answer is 42.85.
<result>A</result>
The distance from City A to City B is 150 miles. While driving from City A to City B, Cara drives at a constant speed of 30 miles per hour. Dan leaves City A 90 minutes after Cara. What is the minimum constant speed in miles per hour that Dan must exceed in order to arrive in City B before Cara?