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? Pick one:	A) 30	B) 40	C) 50	D) 60	E) 70

Rationale: 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 50 t + 25 = 80 t 25 = 30 t 25 / 30 = t 5 / 6 hours = t which is 5 / 6 * 60 = 50 minutes c
Answer: C