Need help in maths !

 i m a commerce student and  not having maths background  so i have found difficulty in quantative apptitute paper. i m going to appear cpt june -13 exam so i have to get atleast 15 marks to clear my exam . due to my office timing i can"t do coahing classess ...can anyone pls tell me some important chapters or topics which i can prepare as i don't have much time.....pls help !