Mary passed a certain gas station on a highway while traveling west at a constant speed of 40 miles per hour. Then, 15 minutes later, Paul passed the same gas station while traveling west at a constant speed of 50 miles per hour. If both drivers maintained their speeds and both remained on the highway for at least 2 hours, how long after he passed the gas station did Paul catch up with Mary?	Choose the correct choice.
A) 1/2 B) 1 C) 3/4 D) 2 E) 3
d = rt   M: r = 40mph, t = t + 1/4hr   d = 40 (t + 1/4)   P: r = 50, t = t   d = 50t   since they went the same distance:   40t + 40/4 = 50t   10t   40  + 40/4= 
<gadget id="calculator">  40  + 40/4</gadget>
<output>50</output>
50t   10t= 10   t = 1 hr,   1
<result>B</result>
Mary passed a certain gas station on a highway while traveling west at a constant speed of 40 miles per hour. Then, 15 minutes later, Paul passed the same gas station while traveling west at a constant speed of 50 miles per hour. If both drivers maintained their speeds and both remained on the highway for at least 2 hours, how long after he passed the gas station did Paul catch up with Mary?