Question

Javier and Serah are both travelling by train. Javier's train travels 130 km in 75 minutes. Serah's train travels 377 km. It leaves at 9:35 and arrives at 12:50. Work out the difference, in km/h, between the average speed of their trains.

Answer 1

12 km/h

Explanation:

Answer 2

The difference between the average speed is 12 kilometers per hour, where Serah's train has the greatest speed.

Explanation:

Givens

• Javier's train travels 130 km in 75 minutes.
• Serah's train travels 377 km from 9:35 to 12:50.

The average speed is defined as

`s=(d)/(t)`

To finde Javier's speed, we need to transform 75 minutes into hours, we know that 1 hour is equivalent to 60 minutes.

`h=75min * (1hr)/(60min) =1.25 \ hr`

Now, we find the average speed

`s_(Javier)=(130km)/(1.25hr)=104 \ km/hr`

Therefore, Javier's train travels 104 kilometers per hour.

On the other hand, Serah's traing travels from 9:35 to 12:50, which is equivalent to 3 hours and 15 minutes, but 15 minutes is equivalent to 0.25, so the total time is 3.25 hours, so the average speed is

`s_(Serah)=(377km)/(3.25hr)= 116 \ km/hr`

So, the difference would be

`116-104=12 \ km/hr`

Therefore, the difference between the average speed is 12 kilometers per hour, where Serah's train has the greatest speed.