you need to work about 12.5 hours because from your gas station job, since you work 30 hours every week, times that by 8.75$ which equals 262.5$ at the end of the week, so subtract 262.5 from 400 which is 137.5, then you need to dived that by 11 since its $ per hour, after doing that you get 12.5 hours, so you would have to work 12.5 hours at your landscaper job