Mathematics 32 Online
OpenStudy (anonymous):

determine the number of possible permutations of two of the five vowels: a, e ,i, o, and u. List them all

OpenStudy (anonymous):

ok, so this is a combinatorial problem

OpenStudy (anonymous):

there are 5 vowels, and they're asking you to choose 2

OpenStudy (anonymous):

okay so would it be 10?

OpenStudy (anonymous):

yes, but you can definitely list them all

OpenStudy (anonymous):

so I would just pick two letter like a and e and then list all the possible letters that can be combined with them

OpenStudy (anonymous):

1. ae 2. ai 3. ao 4. au 5. ei 6. eo 7. eu 8. io 9. iu 10. ou

OpenStudy (anonymous):

exactly

OpenStudy (anonymous):

there is also a formula for this

OpenStudy (anonymous):

http://en.wikipedia.org/wiki/Combination search for the words "Finally there is a formula which exhibits"

OpenStudy (anonymous):

thanks so much!

OpenStudy (anonymous):

well one second

OpenStudy (anonymous):

so if they mean "combinations", then the answer is 10

OpenStudy (anonymous):

however, if they mean permutations, that is iu and ui are different permutations, then the answer would be 20

OpenStudy (anonymous):

since there are 5 possible letters for the first spot, and then 4 possible letters for the second spot. so 5x4 = 20

OpenStudy (anonymous):

in that case, just take the 10 we listed, and reverse the letters for options 11-20

OpenStudy (anonymous):

I think they're asking for the 20 different permutations. since "permutation" and "combination" have different standard meanings in math: http://en.wikipedia.org/wiki/Permutation

OpenStudy (anonymous):

ooo okay

OpenStudy (anonymous):

if they were asking for the 10 we listed, the problem should have said "list all the combinations", not permuations

OpenStudy (anonymous):

so yeah, just take the list, and make sure you have one possibility with the letters reversed for each of the 10 listed

OpenStudy (anonymous):

alrite thanks

OpenStudy (anonymous):

yeah np, good luck!