I need some Graphic Design

Thinking this should be pretty easy. I need to illustrate the math problem at the end of this posting. I will provide the numbers/data necessary, it shouldn't be more than 6 or 7 plain text labels. I may alter it to a turtle race for some variety (also open to other cool ideas to spice it up a little) but the concept will be the same. I've uploaded a very basic example picture, however I will require color, and some more detail. Here is the problem in the event it will help with clarity of what I would like illustrated, however do not worry as I've said I will be providing all labels, this is solely a graphic job, not computational. Two runners are racing on a circular track. The (center of the) outside loop as radius (x) feet and the (center of the) inside loop has radius (y) feet. Runner A is on the outside and runs at velocity (A)laps/hour, and runner B is on the inside loop and runs at velocity (B)laps/hour. If the started the race next to each other, what is the rate of change of the distance between the runners 0.5 hours after the start of the race? Not sure the going rate for this project, if it is above or below range feel free to inbox me/submit other offers. Thanks. Also ideally the shortest possible time frame. Say next 24 hours is preferable, can be up to 72.