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[coolked]

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My exams tomorrow, and I just need to clarify, when does order matter for permutations? What examples constitute as having the order matter? Stupid question but Im freaking out haha

 

[soosoolhastam]

1st, second, third place...

 

[herkulease]

My exams tomorrow, and I just need to clarify, when does order matter for permutations? What examples constitute as having the order matter? Stupid question but Im freaking out haha

a simple example of when order matters would be like a race.

there can only be one person who is 1st, 2nd, 3rd place.

 

[KyoPhan]

1st, second, third place...

5 People competed. How many different combinations can we have for 1st, 2nd, and 3rd place?
In this case, we care about the selection of people AND the order of those people.
n!/(n-r)!
5!/(5-3)! = 5x4x3 = 60

5 people competed. 1st, 2nd, and third place are given prize money. How many combinations are there for people receiving prize money?
In this case, we don't care about the order. We just care about the selection of people.
You can have
Tom, John, Jill as first second and third place respectively and
Tom, Jill, John or many other orders between the 3.

Since order does not matter, these posibilities are counted as 1 selection posibility

n!/(n-r)!r! = 5!/(5-3)!3! = 5!/(2!3!) = 5x4/2 = 10

 

[NewBee12]

Read the question carefully. If there is a condition imposed or a restriction, usually it's a permutation ( order matters )