I have a question here I've been trying to solve to no avail for about a week:

If terry hiked 0.5km/h faster, he would take 1 hour less to complete a 15 hour hike. What was his hiking speed?

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I'm under the impression I use the formula T=D/S, but that's where my problem comes in, I have no idea what the distance is, so the farthest I get is this:

15-1=14 (faster speed time)

14 = *blank*/x+0.5
15 = *blank*/x

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I'm not looking for the end answer, I would just like a little help with how I'm supposed to set up my equations to solve it.

The distance is r\cdot t.

The trip normally takes 15 hours hiking at rate 'r'.

But, it only takes 14 hours hiking at rate 'r+1/2'.

The distance is still the same.

So, we have

14(r+\frac{1}{2})=15r

Solve for r.