A test of 10 questions is chosen from 10 hard questions and 20 easy questions. The salad must have at least 4 hard questions at least 3 easy questions. How many ways can this test be created?
Pick one:
A) 13500611
B) 13200688
C) 13200858
D) 895
E) 7289
Solution: We have four possibilities 4H 6E , 5H 5E, 6H 4E, 7H 3E   (10132008584)(20132008586)+(10132008585)(20132008585)+(10132008586)(20132008584)+(10132008587)(20132008583)=13200858   13200858) 13200858
<result>C</result>
A test of 10 questions is chosen from 10 hard questions and 20 easy questions. The salad must have at least 4 hard questions at least 3 easy questions. How many ways can this test be created?