How to calculate daytime from a graph

[Deathnote777]

I am totally confused, how can i do this question ? Can any1 explain? I cannot understand the answer...

http://imageshack.us/a/img37/4851/img20121118215028.th.jpg

http://imageshack.us/a/img87/5631/img20121118215227.th.jpg

 

[voko]

What course is this from? What have you learned so far?

 

[dextercioby]

Looks astronomy, what book are you using ? Look up the theory once more.