6. A geography student needs to take three 300- level and three 400- level geography classes next semester in order to graduate. If there are 10 300- level courses being offered and 7 400- level courses being offered, how many different schedules could the student have?
Using the Hypergeometric Rule
C_3^10*C_3^(7 )= 10!/3!(10-3)! * 7!/3!(7-3)! = 120(35) = 4200