Hi, I had some luck on this forum before, and here I am stumped again. Hey, I am just learning this stuff. I am not even necessarily looking for an answer, I cant find a formula for this one. It says "A block and tackle system has three pulleys in each of two blocks. If a downward effort of 100 N is applied and the machine has an efficiency of 83.6%, what is the maximum mass that can be moved?" The answers are in kgs. Any thoughts or ANYTHING appreciated!