Question 532645
A committee of 3 people is to be selected from a group of 10 people so that there is one president, one treasurer, and one senator.  In how many ways is this done?
<pre>
You can choose the president any of 10 ways.

For each of those 10 choices, there will remain 9 choices for picking the
treasurer.  That's 10×9 (or 90) ways to pick the president and
treasurer.

For each of those 10×9 or 90 ways to pick the president and treasurer, there
remain 8 ways to pick the senator.  So that's 10×9×8 or 90×8 or 720 ways to
fill all three offices.

Edwin</pre>