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.
You should try and put it in another way it doesn’t make sense
As you can see in the picture, this is 6-8-10 right triangle.
One of angles is 90° so you can find others

8/6 = 4/3
6/8= 3/4
tan-1(4/3) = 36.9 °
tan-1(3/4) = 53.1 °
tan<R= 53.1 °
Hope this helps ^-^
If you divide the area from the length your answer is the height of the triangle.
Since there are 20 students on the field trip. Then 20 is the 100% total. Thus, to find how many people love the museum, we can simply multiply the total number of people by the percentage of interest, namely 40%
20*0.4 = 8
So, 8 people love the museum.