## Trending News

# If the reading club has nine members, how many ways can the club choose five members to attend a special program if order does not matter?

### 6 Answers

- Pramod KumarLv 71 month ago
Answer = 126

It is case of finding combinations of 5 out of 9 members ( since order does not matter). Formula used is -------

.. ... . ...n !

ⁿCᵣ = ------------------- . In this case n = 9 and r = 5

... .. r ! * (n-r) !

................. 9! ................9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1

ie ⁹C₅ = --------------- = ------------------------------------------- = 126

... ... 5! * (9-5)! .... 5 * 4 * 3 * 2 * 1 x 4 * 3 * 2 * 1

Answer = 126

- How do you think about the answers? You can sign in to vote the answer.
- PuzzlingLv 71 month ago
The answer is "9 choose 5"

To calculate that, start by writing 9/5 as a fraction:

9

--

5

Now multiply by the next smaller number on top and bottom. Repeat until you get to 1 on the bottom.

9 * 8 * 7 * 6 * 5

--------------------

5 * 4 * 3 * 2 * 1

If you are doing this by hand, you can cancel everything on the bottom. For example, you can cancel 5 and 5. You can also cancel 8 and 4 * 2. Finally you can partially cancel 9 and 3.

3 * 1 * 7 * 6 * 1

--------------------

1 * 1 * 1 * 1 * 1

Get rid of all the ones.

3 * 7 * 6

= 126 ways

As a double-check, go to Google and type "9 choose 5"

Source(s): https://www.google.com/search?q=9+choose+5