In future, please note that it will be much easier to help you locate your error(s) if you post what you've tried so far.

What "distance" expression did you get for the first time, t, when he was running at r = 6?

What "distance" expression did you get for the rest of the time, 160 - t, when he was jogging at r = 2?

Since the distances were the same, what equation did you get? What solution did you get?

Please be complete. Thank you!