Originally Posted by

**earboth** Hello,

here I am again. I've thought about the function given in your problem. This equation cann't be right.

As I've said in my previous post, this very high speed train travels 7680 miles in 8 hours. That means it has an average speed of 960 miles per hour.

In the air the speed of sound is 745 miles per hour. So this train travels faster than sound. Incredible!

For example: If this train travels 10 hours, then the average speed is nearly twice as high as the speed of sound.

So, please, check the text of your problem. There must be a (minor) mistake.

Greetings

EB