A. 35 because of you look at the line plot it explains how long student are in there for and how many times a day. So you just need to figure out how many students do hw for how long and then multiply that by 10.
Cos(t/2) I got .45 is that what you were looking for or do I need to plug it into the equation up top? can you give me notes of something? cos( -9/11/2) = .45
