1. The problem statement, all variables and given/known data A street light is at the top of a 18 ft tall pole. A woman 6 ft tall walks away from the pole with a speed of 8 ft/sec along a straight path. How fast is the tip of her shadow moving when she is 30 ft from the base of the pole? 2. Relevant equations http://imageiso.com/out.php/i26481_Relatedrates.JPG [Broken] 18/x = 6(x-y) 3. The attempt at a solution y=30 ft simplified 12x=18y tip of shadow will be at 45 ft d/dt 12x = d/dt 18y dx/dt 12 = dy/dt 18 if i plug the 8ft/s as my dx/dt i get a dy/dt of 16/3ft/s but that cant be the right answer since i didnt use the 30ft given in my original question where am i going astray?