Question

A helicopter leaves central airport and flies north at 180 mi/hr. Twenty minutes later a plane leaves the airport and follows the helicopter at 330mi/hr. How long does it take the plane to overtake the helicopter

Answer 1

Explanation:

Let x represent the distance travelled by the helicopter and the plane.

Let t represent the time it takes the the helicopter to travel x miles

Speed of the helicopter is 180 miles per hour.

Distance travelled = speed × time

x = 180t

Twenty minutes later, a plane leaves the airport and follows the helicopter at 330mi/hr. Converting 20 minutes to hours, it becomes 20/60 minutes

Time taken for the plane to travel x miles is t - 20/60

x = 330(t - 20/60)

Before the plane overtakes the helicopter, they would have travelled equal distance. Therefore

330(t - 20/60) = 180t

330t - 110 = 180t

330t - 180t = 110

150t = 110

t = 110/150 = 0.73 hours