Two planes make a 1500 mile flight, one flying 25 miles per hour faster than the other. the quicker plane makes the trip 3 hours faster. how long did it take the slower plane to complete the flight?

1500/25=60
60-3=57
It took 57 hours for the slower plane to complete the flight, and it was flying at 19mph. My question is, how did a plane stay in the sky going only 25 miles per hour? Let alone even 19 miles per hour? I can pedal a bicycle faster than that!