OpenStudy (lexy148):

In how many ways can 3 singers be selected from 5 who came to an audition?

3 years ago
OpenStudy (studygurl14):

5 • 4 • 3 = 60

3 years ago
OpenStudy (studygurl14):

(refresh page if you see question marks)

3 years ago
OpenStudy (lexy148):

i dont get how you got the 4 and 3

3 years ago
OpenStudy (xapproachesinfinity):

Okay you have 5 singer yes?

3 years ago
OpenStudy (xapproachesinfinity):

and you have only 3 sets

3 years ago
OpenStudy (studygurl14):

5 singers, 3 places. 5 options for space#1. 4 left for place #2. and 3 left for place #3

3 years ago
OpenStudy (lexy148):

yes thats correct @xapproachesinfinity

3 years ago
OpenStudy (studygurl14):

cause you can't pick a person twice. make sense?

3 years ago
OpenStudy (xapproachesinfinity):

Yes! like @StudyGurl14 said once the seats are finished we stop counting because we got what we want

3 years ago
OpenStudy (lexy148):

oh okay i got it now thx :)

3 years ago
OpenStudy (anonymous):

Its just from 5 singers you are choosing 3 of them, and order does not matter. so we do the operation 5C3

3 years ago
OpenStudy (xapproachesinfinity):

No its permutation! 5P3

3 years ago
OpenStudy (anonymous):

No it should combinations, because we dont know which one could sing or not, so order does not matter, we can choose any of the 5 people.

3 years ago
OpenStudy (anonymous):

@ganeshie8

3 years ago
OpenStudy (xapproachesinfinity):

that doesn't matter we don't have labels we singer 1 for set one singer two for seat 2 and singer 3 for 3 we have 2 singer left that the same as \(\Large \frac{5!}{(5-3)!}\)

3 years ago
ganeshie8 (ganeshie8):

i feel it should be a combination because of the keyword "selected"

3 years ago
ganeshie8 (ganeshie8):

it could be a permutation also if we are ordering them for singing in the contest

3 years ago
OpenStudy (xapproachesinfinity):

well that's permutation we select the first singers to arrive and count

3 years ago
OpenStudy (xapproachesinfinity):

the total of counting 5 singers is 5! then we need to take out 2! from the total since we have only 3 seats

3 years ago
ganeshie8 (ganeshie8):

selecting "mary, abby, ashley" should not be different from selecting "abby, mary, ashley" since the question doesn't talk about first,second,third places right ?

3 years ago
ganeshie8 (ganeshie8):

if we need to arrange them seats, it becomes a permutation however

3 years ago
ganeshie8 (ganeshie8):

but the question as it stands... im inclining more towards comb

3 years ago
OpenStudy (xapproachesinfinity):

eh i agree with the example you give for this question i believe it's permutation lol

3 years ago
OpenStudy (xapproachesinfinity):

eh okay i changed my mind! after more thinking comb is what fits this

3 years ago
ganeshie8 (ganeshie8):

:) i still feel uneasy though because of the work "audition" audition usually refers to ranking.. thats the reason permutation comes to mind first, but again the question doesn't talk about prizes... so...

3 years ago
OpenStudy (xapproachesinfinity):

hehe! you made feel unsure as well

3 years ago