Question: Walter fell from the eighth platform of some scaffolding and fell past David after falling 4 meters. If he fell for an additional three more times that depth before hitting the ground, and the platforms are evenly spaced out in height, what platform was David on?
How to solve this?
Answer: 
Walter fell 4 meters and an additional three times that depth which is 3*4 = 12 meters
He fell for a total of 4+12 = 16 meters
The eighth platform is 16 meters high and the platforms are evenly spaced so each platform is 16/8 = 2 meters high
David was located 4 meters below the 16 meter level which is 16-4 = 12 meters high
Each platform is 2 meters high so 12 meters would mean the 12/2 = 6th platform