I am brain dead or what

So I have to take a college placement test for school, which would have been okay 6 years ago when I was just out of high school. Now...I'm so out of touch it's embaressing.
 
I got a book from the library andtook one of the exam, and got 21/40, that sad. I feel stupid. Grrs!
 
I never took it in high school because I went military instead of school now I wish I'd taken some more classes.
Better get back to studying 
 
Any ideas?