Two trains leave a station traveling in the same direction. Train A leaves traveling at a constant speed of 50 mph, while train B leaves traveling at a constant speed of 80 mph. If train B left the station 30 minutes after train A left, in how many minutes will train B overtake train A?  Select: A) 30 B) 40 C) 50 D) 60 E) 70
We can use a form of the equation D=RT [distance=rate*time]   Train A will have traveled for 30 minutes longer when train B overtakes it so   time of train A: T + 30 minutes = T + 1/2 hours (switch to hours since the rates are in hours)   time of train B: T   rate of train A: 50 mph   rate of train B: 80 mph   the distance traveled by each will be the same when B overtakes A so set the right side of D=RT equal to each other for the two trains   50*(T+1/2)=80*T   50T+25=80T   25=30T   25/30=T   5/6 hours = T which is 5/6*60= 
<gadget id="calculator">5/6*60</gadget>
<output>50</output>
50 minutes   50
<result>C</result>
Two trains leave a station traveling in the same direction. Train A leaves traveling at a constant speed of 50 mph, while train B leaves traveling at a constant speed of 80 mph. If train B left the station 30 minutes after train A left, in how many minutes will train B overtake train A?