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?  Select the correct option.
A) 1 hr  B) 3 hr  C) 2 hr  D) 6 hr  E) 8 hr
A   1 hr   Let the duration of the flight be x hours. Then,   600/x - 600/(x + 1/2) = 200   x(2x + 1) = 3 2x2 + x - 3  (2  + 1)= 
<gadget id="calculator"> (2  + 1)</gadget>
<output>3</output>
3 2x2 + x - 3= 0   (2x + 3)(x - 1) = 0   x = 1 hr
<result>A</result>
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?