Mr and Mrs Smith have invited 9 of their friends and their spouses for a party at the Waikiki Beach resort. They stand for a group photograph. If Mr Smith never stands next to Mrs Smith (as he says they are always together otherwise). How many ways the group can be arranged in a row for the photograph?

Question

Mr and Mrs Smith have invited 9 of their friends and their spouses for a party at the Waikiki Beach resort.  They stand for a group photograph.  If Mr Smith never stands next to Mrs Smith (as he says they are always together otherwise). How many ways the group can be arranged in a row for the photograph?

anonymous · Answer

can anybody explain this for me

jack1 · Answer

@terenzreignz can you help att all dude... something to do with permutations or factorials

jack1 · Answer

20ppl all up A and B never beside

terenzreignz · Answer

Oh... Jack is quite right, permutations are key here... before we proceed, CAN you do permutations, @ashishraj969 ?
$$\Large _nP_r = \frac{n!}{(n-r)!}$$

terenzreignz · Answer

Hey @Jack1 looks like ashishraj is unavailable, but can you do this question? Just for fun ^_^

jack1 · Answer

aye, just finishing another q, qill give it a shot straight after dude, cheers

terenzreignz · Answer

mhmm :)

terenzreignz · Answer

Wait, what? Not following :>

terenzreignz · Answer

What do those letters mean? D:

terenzreignz · Answer

Oh okay, nvm.

terenzreignz · Answer

yeah, figured^
Okay :)

terenzreignz · Answer

yeah, 20 factorial as you said lol

jack1 · Answer

sweet, cheers @terenzreignz

terenzreignz · Answer

wait, that's not the answer yet D:

terenzreignz · Answer

hang on... :)

terenzreignz · Answer

Well, that just means the original asker could get the answer without putting any work to it :(

jack1 · Answer

nuh, u lost me again tj, sorry