Train A left station T at 3:30 p.m. and traveled on straight tracks at a constant speed of 60 miles per hour. Train B left station T on adjacent straight tracks in the same direction that train A traveled on. Train B left station T 40 minutes after train A, and traveled at a constant speed of 75 miles per hour. Train B overtook train A on these straight tracks. At what time did train B overtake train A? Choose the correct choice from the following answers.
A) 4:10
B) 5:40
C) 6:10
D) 6:50
E) 7:30
Train A left 40 mins before Train B at a speed of 60 mph   So distance traveled by Train A in 40 mins= 40 miles   Let's say the total distance at the point of overtaking is x   So, the time taken for covering the remaining distance x-40 by Train A=x-40/60   Time taken for covering the distance x at 75 mph by Train B=x/75   Both Time should be equal which gives us,   x-40/60=x/75   x=160 mins=2 hr 40 mins   Time when train B overtake train A = 3:30+40 mins+ 2 hr 40 mins= 6:50   Correct Answer is 6:50.
<result>D</result>
Train A left station T at 3:30 p.m. and traveled on straight tracks at a constant speed of 60 miles per hour. Train B left station T on adjacent straight tracks in the same direction that train A traveled on. Train B left station T 40 minutes after train A, and traveled at a constant speed of 75 miles per hour. Train B overtook train A on these straight tracks. At what time did train B overtake train A?