Question

In a flight of 600km,an aircraft was alowed down due to bad weather. Its average speed for the trip reduced to 200km/hr and the time increased by 30 minutes. Find the duration of the flight.

Answer 1

The duration of the flight is 1 hour

Explanation:

Since average speed = distance traveled / time

Let the duration of the flight be in z hours

So, (600km/z hours) - (600km/ z hours + (1/2)) = 200km/hr

Note: 1/2 is used as a result of 30 minutes increased in time which is half an hour.

200 = (600/z ) - (600/z + (1/2))

Multiply 2 through on (600/z + (1/2))

200 = (600/z ) - (1200 / (2z + 1))

Divide through by 200

= z(2z + 1) = 3

convert to quadratic equation

2z² + z = 3

2z² + z - 3 = 0

(2z + 3) ( z-1) = 0

z-1 = 0

z = 1 hour