I agree. I thought some of the questions were ambiguous or were hard to comprehend.
The answers were unorganized, too. For instance, one of the answers would cite the answer to be "B", then explain the calculation for the answer -- but the correct answer would actually be "E" instead of "B". I also found some answers with the correct formulations, but incorrect calculations.
I definitely don't regret buying it - it is only 8 bucks.