Question

The train travel the first 30 km of 120km track with a uniform speed of 30km/hr what should be the speed of the train to cover the remaining distance of the track so that it's average speed is 60km/hr for the entire trit​

Answer 1

Answer:

60 km/hr is the answer so its avarage speed is 60km/hr

Answer 2

Answer:

Explanation:

The formula for average speed is,

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

Time taken to cover the first 30 km at the speed of 30 km/h =

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

⇒ $Time = \frac{30}{30}hr$

⇒$Time = 1hr$

Let the time taken for the next 90 km be t.

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

⇒ $60 = \frac{120}{1+t}$

⇒ $1+t = \frac{120}{60}$

⇒ $1+t = 2$

⇒ $t = 1$

We get the time as 1 hr for the remaining of 90km journey.

Now,

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

⇒ $Speed = 90 km/h$

Answer = 90km/h