Can Somone please help, im nervous about the A+ test

Hello everyone, i just recently graduated a 9 month program at katharine gibbs tech school. i have a VERY good job lined up but i need to be A+ certified... i took MANY practice test and honestly, nothing i learned in school was covered on these prac test.. i took out books from the library all from 1999 and the questions are ridiculous.. i never heard of any of them. but, there is one site, www.passitnow.com that i can take there practice A+ test and get no lower then 90's on them but the other practice test i cant even seem to get 10 right... now, what should i do??? i dont have the money to blow, and if i fail, my dad said he makin me go back to school for another 2 years.. i really dont want to do that.. any advice?