Mon 2 Mar, 2015 11:12 am - I came up with:
Ways to pick only questions that he can answer = 9x8x7x6x5x4x3 / 7! (because the order doesn't matter)
Total ways to pick 7 questions =15x14x13x12x11x10x9 / 7!
Prob is... (view)
Mon 2 Mar, 2015 10:18 am - The prof gives his class 15 questions in advance of the exam and announces he will randomly pick seven of the questions to be on the exam.
Joe can correctly answer 9 of the 15. What are the... (view)
