# Thread: Quick stat/factoral questions? Possible explanation?

1. ## Quick stat/factoral questions? Possible explanation?

how many possible 5 digit zip codes are there if numbers can't be repeated?

how many ways can 7 different items be arranged in a single line? (is that 7 factorial?)

how many ways can i select 5 different objects out of 12 objects total?

2. Originally Posted by thecleric
how many possible 5 digit zip codes are there if numbers can't be repeated? Mr F says: (10)(9)(8)(7)(6) = ...... if a zip code can start with 0, (9)(9)(8)(7)(6) = ...... otherwise.

how many ways can 7 different items be arranged in a single line? (is that 7 factorial?) Mr F says: Yes.

how many ways can i select 5 different objects out of 12 objects total? Mr F says: $\displaystyle {\color{red} {12 \choose 5}}$
..

3. yeah zip codes are example of permutations...wikipedia solved that one for me. about third one...

bad wording,

how about:
if you have 12 flowers, how many different ways can you select 5 of them for display

4. Originally Posted by thecleric
yeah zip codes are example of permutations...wikipedia solved that one for me. About third one...

Bad wording,

how about:
If you have 12 flowers, how many different ways can you select 5 of them for display
$\displaystyle ^{12}\text{P}_5$

5. lol sorry, but 12 to the power of 5? or 5 to the power of 12?

6. Originally Posted by thecleric
lol sorry, but 12 to the power of 5? or 5 to the power of 12?
Read section 2: Permutation - Wikipedia, the free encyclopedia

I had thought the notation would be familiar ....

7. oops didn't see the older notation part...thanks