Two airplanes fly the same exact route from Atlanta to Chicago. Plane A flies 200 mph while plane B flies 300 mph (assume that simple model versus actual acceleration/deceleration near the airports). If plane A took off exactly 40 minutes before plane B, after how many minutes will plane B overtake plane A?	Select the correct option.
A) 65
B) 80
C) 90
D) 115
E) 120

Rationale: we can use some form of the equation d = rt [ distance = rate * time ] rate of plane a : 200 mph rate of plane b : 300 mph plane a will be in the sky 40 minutes longer than plane b ( 2 / 3 of an hour ) time of plane a when b overtakes it : t + ( 2 / 3 ) use 2 / 3 of an hour since the rate is in hours time of plane b when b overtakes a : t at the time that b overtakes a , they will have travelled the same distance so rt is equal for each plane : 200 * ( t + 2 / 3 ) = 300 * t 200 t + 400 / 3 = 300 t 400 / 3 = 100 t 4 / 3 = t this is 1 and a third hour , so 60 minutes + 20 minutes = 80 minutes b
Answer: B