A fraternity is to elect a president and a treasurer from the group of 40 members. How many ways can those two officers can be elected?

Question

kinged · Answer

That's just a combination.
There's actually a symbol for it on the calculator.

kinged · Answer

The symbol is nCr which just means "Choosing n objects from r total of objects".

kinged · Answer

Do that for the president and then the total number is 40-1 (since you just took a person from the forty) and then do the calculation for the treasurer. Then you multiply both.

kinged · Answer

So, 1C40 for president and 1C39 for Treasurer, then you just multiply.

mathstudent55 · Answer

Try 40C1 * 39C1

mathstudent55 · Answer

Or you can just think this way:
You have 40 choices for the president.
Then you have 39 choices left for the treasurer.
The answer is 40 * 39