Question

In a flight of 600 km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 200 km/hr and the time of flight increased by 30 minutes. The duration of the flight is (in hours):

Answer 1

x=average speed

x-200=reduced average speed

600%2F%28x-200%29-600%2Fx=30%2F60=1%2F2

lcd:x(x-200)

600x-600(x-200)=(x^2-200x)/2

600x-600x+120000=(x^2-200x)/2

x^2-200x-240000=0

(x+400)(x-600)=0

x=-400(reject)

or

x=600

x-200=400 (reduced speed)

travel time=distance/speed

600/400=3/2=1.5

duration of the flight is: 1.5 hr