In a flight of 600 km, an aircraft was slowed due to bad weather. Its average speed for the trip was reduced to 200 km/hr and time of flight increased by 30 minutes. Find the original duration of flight.

Answer: The original duration of flight was 1 hour.

Step-by-step solution

Step 1: Define variables and formulate equations

We need to find the original duration of the flight. Let's denote the original speed of the aircraft as vv km/hr and the original time taken as tt hours. The total distance of the flight is given as 600 km.

Step 2: Set up equations based on given information

The fundamental relationship between distance, speed, and time is Distance=Speed×Time\text{Distance} = \text{Speed} \times \text{Time}. So, for the original flight, we have v⋅t=600v \cdot t = 600. Due to bad weather, the speed was reduced by 200 km/hr, making the new speed v−200v - 200. The time of flight increased by 30 minutes, which is 0.5 hours, so the new time is t+0.5t + 0.5. The distance remains 600 km, leading to the second equation: (v−200)(t+0.5)=600(v - 200)(t + 0.5) = 600.

Step 3: Substitute and simplify the equations

From equation (1), we can express vv as v=600tv = \frac{600}{t}. Substitute this expression for vv into equation (2). This will give us an equation solely in terms of tt. Expand the equation and simplify.

Step 4: Form a quadratic equation in terms of t

Continue simplifying the equation. Multiply the entire equation by tt to eliminate the fraction, and then rearrange the terms to form a standard quadratic equation of the form at2+bt+c=0at^2 + bt + c = 0. Divide by -100 to simplify the coefficients.

Step 5: Solve the quadratic equation for t

We have a quadratic equation 2t2+t−3=02t^2 + t - 3 = 0. We can solve this using the quadratic formula t=−b±b2−4ac2at = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}, where a=2a=2, b=1b=1, and c=−3c=-3. Calculate the two possible values for tt.

Step 6: Determine the valid duration

We get two possible values for tt: 11 hour and −1.5-1.5 hours. Since time cannot be negative, we discard the negative solution. Therefore, the original duration of the flight is 1 hour.

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