i found them to be completely trash...i took the science portion and as i was grading myself, i was getting questions wrong left and right...but when i went back to look at the answer choices, i'd say 80 percent of the their answer key is wrong....the one i used was at barnes and noble and was written in the 90s...im not sure if they've updated it or not
if you've got a LOT of time left, i'd say go ahead and use it, but make sure to double check all of the answers