Question

A train covered a certain distance at a uniform speed if the train had been 5 km/h hour faster it would have taken 3 hours less than the the scheduled time and if the train were answer by 4km/h , it would have taken 3 hours more than the scheduled time. find the length of the journey???​

Answer 1

Answer:

Subtract 3 from -7 on number line

Answer 2

If I will take question like this.... A train covered a certain distance at a uniform speed. If the train would have been 6 km/h faster, it would have taken 4 hours less than the scheduled time. And, if the train were slower by 6 km/h, it would have taken 6 hours more than the scheduled time. Find the length of the journey.



Then answer would be


Let the actual speed of the train be x km/hr and the actual time taken be y hours. Then,
Distance covered =(xy)km ..(i) [∴ Distance = Speed × Time]

If the speed is increased by 6 km/hr, then time of journey is reduced by 4 hours i.e., when speed is (x+6)km/hr, time of journey is (y−4) hours.

∴ Distance covered =(x+6)(y−4)
⇒xy=(x+6)(y−4) [Using (i)]
⇒−4x+6y−24=0
⇒−2x+3y−12=0 ..(ii)

When the speed is reduced by 6 km/hr, then the time of journey is increased by 6 hours i.e., when speed is (x−6) km/hr, time of journey is (y−6) hours.

∴ Distance covered =(x−6)(y+6)
⇒xy=(x−6)(y+6) [Using (i)]
⇒6x−6y−36=0
⇒x−y−6=0 (iii)

Thus, we obtain the following system of equations:
−2x+3y−12=0
x−y−6=0

By using cross-multiplication, we have,
3×−6−(−1)×−12
x
​
=
−2×−6−1×−12
−y
​
=
−2×−1−1×3
1
​


⇒
−30
x
​
=
24
−y
​
=
−1
1
​


⇒x=30 and y=24

Putting the values of x and y in equation (i), we obtain
Distance =(30×24)km =720km.

Hence, the length of the journey is 720km.





I found this for you
Hope it will help you thanks