Question

3. A plane flies a distance of 1600 km at a certain
speed. On the return journey, due to bad
weather, as the speed was reduced by 40 km/h
it took 1 hour 20 minutes more than the onward
journey. Find the speed of the onward journey.​

Answer 1

Answer:

240 kmph

Step-by-step explanation:

Distance = 1600 km

Let the speed in onward journey = s kmph

As time = Distance/speed

so, time in onward journey = 1600/s hr

According to question;

Speed reduced in return journey by 40 kmph

so, speed in return journey = ( s - 40) kmph

In return journey time taken = 1600/s + 1 hour 20 minutes

so, T = ( 1600/s + 4/3 ) hour

Also, time in return, T = 1600/( s - 40 ) h

Hence, equating time of return journey, we get

( 1600/s + 4/3 ) = 1600/( s - 40 )

so, 1600/( s - 40 ) - 1600/s = 4/3

or, 1600 [ ( s - s + 40 )/(s^2 - 40s) ] = 4/3

or, 1600/ (s^2 - 40s) = 1/3

or, s^2 - 40s - 48000 = 0

or, ( s - 240)( s + 200 ) = 0

So, speed , s = 240 kmph

( as speed can't be negative so, -200 neglected)

Hence, speed of onwards journey is 240 kmph.

Answer 2

Answer:

240 bud use your brains bishhh