I completed the SIR exam with my girlfriend, it's honestly pretty easy.
A few of the questions CAN be a little technical but you've got the whole internet at your disposal.
You can also return to the exam at ANY time. Easiest thing to do is to open up google, and search specifically on the serving it right website for keywords from the question... ex)
Go to google and type...
"site:
Serving It Right - Home [insert keywords here]"
Good luck.