#Hello, can someone help solve and explain one of the Factorial problems.

19 messages · Page 1 of 1 (latest)

plain smelt
grave trellisBOT
plain smelt
#

I'm mostly confused on the first one, I would be grateful if you guys can help.

tribal torrent
#
  1. for the just do it by writing how many options there are for each space
  2. treat the science posters as one object
  3. since it how many AREN'T, it will be the complement
stuck kestrel
#

It is clear that whether you place them at the left end or the right, the number of arrangements will be the same. So just find the number of arrangements for one end and multiply by 2.

plain smelt
#

So, will it be 4 x 4! on (a)?

tribal torrent
#

no, it will be 2 x ... x 1 for math posters, because there is only two options for the first spot (one of the two maths posters), and one for the last one, as there is one maths poster left, and that is the only thing that can go on the end

#

in case you are confused "..." is stuff other than the maths posters in the above message

plain smelt
#

So it's 2 x 4! = 48?

tribal torrent
#

yes

#

2 * 4 * 3 * 2 * 1 * 1

plain smelt
#

Ah, I get it much clearer now, thank you very much.

tribal torrent
#

( 2 math ) * ( 4 not maths ) * ( 3 not math ) * ( 2 not math ) * ( 1 not math ) * ( 1 math )

#

ye

#

np

#

for b) treat all the science posters as one as one object, but dont forget to account for their rearrangements

plain smelt
#

Then it's 6 x 4 x 3!?

spiral vessel
#

.close