Question

If the speed of a car is decreased by 8 km/h, it takes 1 hour more to cover a

distance of 240 km. Find the original speed of the car.

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Answer 1

Answer:

Let the speed of car be xkmph

Let it takes Time t hrs to cover the distance of 240km

⟹xt=240⋯(1)

speed is decreased by 8⟹x−8

Time is increased by 1⟹t+1

it covers the same distance so (x−8)(t+1)=240

xt+x−8t−8=240

From (1)⟹x−8t−8=0

x=8t+8

Put it in (1)⟹(8t+8)(t)=240

t ²+t−30=0

t ²+6t−5t−30=0

t(t+6)−5(t+6)=0

(t−5)(t+6)=0

t=5,−6

Time cannot be negative so t=5

Put it in (1)

⟹x(5)=240⟹x=12kmph

I hope it help you..