Answer:
The duration of the flight is 1 hour
Step-by-step 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
