How exactly do i go about solving these questions:an example would be fine ;)

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- March 26th 2006, 01:09 PMArbiturPermutations.. a quick question
How exactly do i go about solving these questions:an example would be fine ;)

- March 26th 2006, 01:13 PMTD!
Example:

- March 26th 2006, 01:14 PMArbitur
you dont have to use one of my questions but can u do an example with numbers? id understand more

- March 26th 2006, 01:16 PMTD!
Just replace n by a number to see an example, e.g. n = 5:

- March 26th 2006, 01:20 PMArbitur
thanks... im having trouble with this one too.. funny how i get all the hard questions but not these anyways no solving needed here just an example will do( my book sucks)

- March 26th 2006, 01:22 PMTD!
The first one is exactly 5!, no?

Let's take a look at the second one. It starts like 8!, but that is 8*7*6*5*4*3*2*1. But the last part 5*4*3*2*1 isn't there, and that's exactly 5!. So we need 8!, but not the 5!, so 8!/5!. Check:

- March 26th 2006, 01:24 PMArbitur
so say it was 30*29 whats the answer?

- March 26th 2006, 01:25 PMTD!
Try the same approach as above.