Question

You are watching the Chicago marathon from your friend's apartment, 100 feet above the street. A runner passes the building at 11 feet/sec. Let d denote the distance between the base of the building and the runner, and let h denote the distance between you and the runner. How fast is the distance between you and the runner changing 20 seconds after she passed the building?
hw
did you get it?
hw
I got 220, did you?
I think mines is wrong though