Question

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In a fight of 600km, 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. Find the duration of flight.




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Answer 1

Answer:

Let the original speed of the aircraft be x km/hr.

then new speed =(x−200) km.hr

Duration of light at original speed = ( 600/x ) hr

Duration of fight at reduced speed = ( 600/x-200 ) hr

600/x - 200 - 600/x = 1/2

So, the origianl speed of the aircraft was 600km/hr

hence, duration of flight = ( 600/x ) hr = ( 600/60 ) hr = 1hr

1 hr = Answer

hope it helps you

Answer 2

Let the original speed be a km/h.

∴ Duration of flight = (600/a) hr.

Since the speed was decreased by 200 km/h,

the new speed of the aircraft = (a-200) km/h.

So, the duration of flight after reduction in speed

= (600/a-200) hr.

30 minutes = 1/2 hrs.

So, from the above data, we can write the equation-

(600/ a-200)-(600/a) = 1/2

⇒ {600x-600(a-200)}/a(a-200) = 1/2

⇒ 120000/a²-200a = 1/2

⇒ a²-200a-240000 = 0

⇒ a²-600a+400a-240000 = 0

⇒ (a-600)(a+400) = 0

⇒ a = 600, -400

Here, a = 600 and  -400, but since a is the speed and speed can't be negative, therefore we have to take a = 600.

Hence, the original speed of aircraft = a km/h = 600 km/h.

∴ Duration of flight = (600/600) hr. = 1 hr.

Hence, the duration of the flight is 1 hour.