distance = speed * time
The plane catches the helicopter when they both traveled the same distance, d.
The helicopter traveled t hours, but the plane traveled 1 hour less, or t - 1 hours.
helicopter:
d = 180t
plane:
d = 330(t - 1)
The distance they both traveled, d, is the same, so
180t = 330(t - 1)
180t = 330t - 330
-150t = -330
t = (-330)/(-150)
t = 2.2
The helicopter traveled 2.2 hours, so the plane traveled 1.2 hours.
Answer: The plane catches the helicopter after 1.2 hours of plane flight.
