In a flight of 900 km, Air-India Express was slowed down due to bad weather.…
2024
In a flight of 900 km, Air-India Express was slowed down due to bad weather. Its average speed for the trip was reduced by 300 km/hr and the time of flight increased by 30 minutes. What is the duration of the flight?
- A.
2 hrs
- B.
3 hrs
- C.
3.5 hrs
- D.
1.5 hrs
Attempted by 2 students.
Show answer & explanation
Correct answer: D
Step-by-Step Solution
To find the actual duration of the flight, we can set up an algebraic equation based on the relationship between distance, speed, and time.
Define the variables:
Let the original duration of the flight be x hours.
The increased duration due to bad weather is x + 0.5 hours (since 30 minutes = 0.5 hours).
Total distance = 900 km.
Set up the speed equation:
The difference in speed is 300 km/hr.
900/x - 900/(x + 0.5) = 300
Solve for x:
Divide the entire equation by 300:
3/x - 3/(x + 0.5) = 1
3 * (x + 0.5) - 3x = x * (x + 0.5)
3x + 1.5 - 3x = x^2 + 0.5x
x^2 + 0.5x - 1.5 = 0
Multiply by 2 to clear decimals: 2x^2 + x - 3 = 0
Factor the quadratic equation: (2x + 3)(x - 1) = 0
Since time cannot be negative, x = 1 hour.
Calculate the actual duration:
The actual duration of the flight is the increased time: x + 0.5 = 1 + 0.5 = 1.5 hours.