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. What is the duration of the flight ?  Pick one:
A) 3 hours	B) 2.4 hours	C) 1.4 hours	D) 1 hour	E) None of these
Explanation:   Let the duration of the flight be x hours.   Then   600/x−600 /x+1/2=200   600/x−1200 /2x+1=200   x(2x+1)=3   2x2+x−3 (2 +1)= 
<gadget id="calculator"> (2 +1)</gadget>
<output>3</output>
3   2x2+x−3=0   =&gt;(2x+3)(x−1)=0   Neglecting the negative value for x we get x = 1   Option 1 hour
<result>D</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. What is the duration of the flight ?