1.  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 :
A. 1 hour
B. 2 hours
C. 3 hours
D. 4 hours

Answer: Option A

Explanation:

Let the duration of the flight be x hours.

Then, 600 - 600 = 200
x x + (1/2)

600 - 1200 = 200
x 2x + 1

x(2x + 1) = 3

2x2 + x - 3 = 0

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

x = 1 hr.      [neglecting the -ve value of x]