Question 1064616
In how many ways can a committee of 5 be formed from 5 juniors and 7 seniors if the committee must have 3 seniors?
<pre><b>
Case 1:  The committee consists of 3 seniors and 2 juniors.
Case 2:  The committee consists of 4 seniors and 1 junior.
Case 3:  The committee consists of 5 seniors and 0 juniors.


7C3&#8729;5C2 + 7C4&#8729;5C1 + 7C5&#8729;5C0 = 35&#8729;10 + 35&#8729;5 + 21&#8729;1 = 350 + 175 + 21 = 546 ways

Edwin</pre></b>