Quick stat/factoral questions? Possible explanation?

• March 5th 2009, 12:27 AM
thecleric
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?
• March 5th 2009, 02:38 AM
mr fantastic
Quote:

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: ${\color{red} {12 \choose 5}}$

..
• March 5th 2009, 02:47 AM
thecleric
yeah zip codes are example of permutations...wikipedia solved that one for me. about third one...

if you have 12 flowers, how many different ways can you select 5 of them for display
• March 5th 2009, 02:51 AM
mr fantastic
Quote:

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

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

$^{12}\text{P}_5$
• March 5th 2009, 02:55 AM
thecleric
lol sorry, but 12 to the power of 5? or 5 to the power of 12?
• March 5th 2009, 03:19 AM
mr fantastic
Quote:

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 ....
• March 5th 2009, 03:34 AM
thecleric
oops didn't see the older notation part...thanks