how do you do a problem like this?

720m/day=?m/mm

your units don't match and make no sense.

did you mean 720 m/day = ? m/minute?

there are 24*60 minutes in a day.

so 720 m/day = 720 m/1440 minutes
=1/2 m/minute

thanks for your help my teacher has me screwed up.