Question

79. In a flight of 600 km, an aircraft was slowed down due to bad weather.
The average speed of the trip was reduced by 200 km/br and the time of
flight increased by 30 minutes. Find the duration of flight,
points A 3. 4) and
​

Answer 1

Answer:

ANSWER

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

then new speed =(x−200) km.hr

Duration of flight at original speed =(

x

600

)hr

Duration of fight at reduced speed =(

x−200

600

)hr

∴

x−200

600

−

x

600

=

2

1

⇒

x(x−200)

600x−600(x−20)

=

2

1

⇒

x

2

−200x

120000

=

2

1

⇒x

2

−200x−240000=0⇒x

2

−600x+400x−240000=0

⇒(x−600)(x+400)=0⇒x=600orx=−400⇒x=600

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

hence, duration of flight =(

x

600

)hr=(

60

600

)hr=1hr

so, your answer is 1 hr