Hendree Milward, one of our wondeful math faculty has posted the escalator problem:

Escalator Problem
Adrian is at the top of descending escalator, and his son Brad is at the bottom.
Adrian starts walking down the escalator, and counts 40 steps when he reaches the bottom. Brad starts running up the escalator, at three times the speed his father is walking down, and counts 72 steps when he reaches the top.
How many steps are visible when the escalator is stopped?