Rational Expressions, Equations, and Functions

Question

Moving sidewalks. The moving sidewalk at O'Hare Airport in Chicago moves 1.8ft/sec. Walking on the moving sidewalk, Roslyn travels 105ft forward in the time it takes to travel 51ft in the opposite direction. How fast so we Roslyn walk on a nonmoving sidewalk?

Answer 1

This problem is solved with the same format as the plane against/with the wind or the boat with/against the current.

105 = (r + 1.8)t, 105 / (r + 1.9) = t

51 = (r - 1.8)t : 51 / (r - 1.8) = t

Set the two t's equal and solve for r.