This is a very simple question, however having all the words are pretty confusing, right? Don't worry I am going to break it down. First thing you want to do is forget about how many stories are how many feet, because you are trying to find that but are probably getting very confused. So write down that the word EACH= 1-story, Then have 1-story= 15ft. so basically you add 15 to every story. 1=15, 2=30, use this to find the answers 15x= ft---> 15(10)=150ft---> do the last one. If you anymore questions I will break it down further, I used to have a hard time with these.