Question

A train travels a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, then it would have take?​

Answer 1

$\huge\underline\mathrm{Question}$

A train travels a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, then it would have take?

$\huge\underline\mathrm{Solution}$

Let us consider,

speed of train = x km/h

And

Time taken to travel 480 km = 480x km/h

As per second condition, the speed of train = (x – 8) km/h

Also given, the train will take 3 hours to cover the same distance.

Therefore, time taken to travel 480 km = 480x + 3 km/h

As we know,

$\boxed{Speed × Time = Distance}$

Therefore,

(x – 8)(480/x + 3) = 480

⇒ 480 + 3x – 3840/x – 24 = 480

⇒ 3x – 3840/x = 24

⇒ 3x² – 8x – 1280 = 0

Therefore,

the speed of the train, satisfies the quadratic equation 3x²– 8x – 1280 = 0.

Answer 2

Step-by-step explanation:

A train travels a distance of 480 km at a uniform speed. If the speed had been 8 km/h less, then it would have take?

\huge\underline\mathrm{Solution}

Solution

Let us consider,

speed of train = x km/h

And

Time taken to travel 480 km = 480x km/h

As per second condition, the speed of train = (x – 8) km/h

Also given, the train will take 3 hours to cover the same distance.

Therefore, time taken to travel 480 km = 480x + 3 km/h

As we know,

\boxed{Speed × Time = Distance}

Speed×Time=Distance

Therefore,

(x – 8)(480/x + 3) = 480

⇒ 480 + 3x – 3840/x – 24 = 480

⇒ 3x – 3840/x = 24

⇒ 3x² – 8x – 1280 = 0

Therefore,

the speed of the train, satisfies the quadratic equation 3x²– 8x ❤✌