Question

एक रेलगाड़ी 480km की दूरी समान चाल से तय करती है यदि इसकी चाल 8km/h कम हो तो वह उसी दूरी को तय करने मे 3घंटे अधिक लेती हमे रेलगाड़ी की चाल ज्ञात करनी है ​

Answer 1

Answer:

The original speed of train is 32 km/h.

Step-by-step explanation:

Distance = 480 km

Let the speed of the train be x

Time = $\frac{Distance}{Speed}$

Time = $\frac{480}{x}$

We are given that the speed is reduced by 8 km/h

So, new speed = x-8

Time = $\frac{480}{x-8}$

Now we are given that when the speed is reduced by 8 km/h so, it will takes 3 hours more.

$\frac{480}{x-8}-\frac{480}{x}=3$

$\frac{480x-480x+3840}{(x)(x-8)}=3$

$\frac{3840}{x^2-8x}=3$

$3840=3x^2-24x$

$3x^2-24x-3840=0$

$x^2-8x-1280=0$

$x^2-32x+40x-1280=0$

$x(x-32)+40(x-32)=0$

$(x-32)(x+40)=0$

$x=32,-40$

Since the speed cannot be negative

So, The original speed of train is 32 km/h.