Question 1161689
<pre>
If there did not need to be at least one junior, the answer would be

10 students CHOOSE 5, or 10C5 = 252 ways.

From that number we must subtract the number of committees consisting of all
seniors and no juniors, which would be

6 seniors CHOOSE 5, or 6C5 = 6 

Answer: 252-6 = 246 ways.

Edwin</pre>