Need help with question for sac study

[tim8899]

Hey guys, im new on this site and dont really know what im doing, but would anyone be able to have a look at this and tell me if im on the right track? im pretty sure i know how to do part a but im not really sure what part b is asking me... (i have attached photos of questions)

also if anyone has any tips about how to work out what a worded question is asking, that would be awesome!

[fred42]

Please see attached.