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?

  1. A.

    2 hrs

  2. B.

    3 hrs

  3. C.

    3.5 hrs

  4. 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.

  1. 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.

  2. Set up the speed equation:

    • The difference in speed is 300 km/hr.

    • 900/x - 900/(x + 0.5) = 300

  3. 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.

  4. Calculate the actual duration:

    • The actual duration of the flight is the increased time: x + 0.5 = 1 + 0.5 = 1.5 hours.

Explore the full course: Amcat Preparation