Question

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:
1. 1 hr
2. 2 hr
3. 3 hr
4. 4 hr

Answer 1

Correct Answer - Option 1 : 1 hr

Given:

Its average speed for the trip was reduced by 200 km/hr and the time of flight increased by 30 minutes

Concept:

Speed = Distance/Time

Calculation:

Let be the original speed of aircraft be x km/h

⇒ Due to bad weather new speed = (x - 200) km/h

⇒ The time is taken by flight at original speed = 600/x

⇒ Time is taken by flight at new speed = 600/(x - 200)

⇒ Now the total time difference = 30 minutes = 1/2 hours

⇒ 600/(x - 200) - 600/x = 1/2

⇒ By solving the equation

⇒ x = 600, -400

⇒ The time is taken by aircraft at original speed = 600/600 = 1 hours

∴ The required result will be 1 hour.