You are confusing two different tests. The "Crack the GMAT" tests are NOT the same as Princeton Review
's "Cracking the GMAT
" tests. The other company is banking on PR's name to confuse people. I'm surprised PR hasn't sued them.
Any test that tells you it's 100 points off isn't worth taking. Take the real Cracking the GMAT
tests (they are much better and your PR scores will be a LOT closer to your real score) and GMATPrep.