Denny and john leave a station at different times with both travelling in the same direction. Denny walks 60 m per minute, and John cycles 210 m per
minute. If Denny has already waled 1800 m how many minutes will it take for John to catch up with Denny by bike? If John stars by bike 14 minutes after denny departed, how many minutes will it take john to catch up with denny?