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? Pick
A) 65  B) 80  C) 90  D) 115  E) 120
We can use some form of the equation D=RT [distance = rate * time]   rate of plane A: 200 mph   rate of plane 80: 300 mph   Plane A will be in the sky 40 minutes longer than plane 80 (2/3 of an hour)   time of plane A when 80 overtakes it: T+(2/3) use 2/3 of an hour since the rate is in hours   time of plane 80 when 80 overtakes A: T   At the time that 80 overtakes A, they will have travelled the same distance so RT is equal for each plane:   200*(T+2/3) = 300*T   200T + 400/3 = 300T   400/3 = 100T   4/3 = T   this is 1 and a third hour, so 60 minutes + 20 minutes = 80 minutes   80
<result>B</result>
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?