Simple problem?

[Ergot]

In how many distinct ways can three purple and two pink balls be arranged in a row?

I think you guys can figure it out pretty easily... but I'm too stupid to so help :P!

[deadly7]

Six.

P = purple
I = pink

PIPIP
PIPPI
PIIPP
IPPPI
IPPIP
IIPPP

Incidentally, there's an easier way than thinking about every combination.  Multiply the two numbers.

[Ergot]

What about PPIPI, PIIPP, PPIIP, etc?

[Joe]

deadly got owned.

Incidentally, Ergot, PIIPP was included. Also, PPIIP is simply PIIPP backwards, but I don't know if you want those or not.

I think the formula deadly gave is the "I have X pairs of pants and Y shirts. How many outfits can I make?" formula. Going by that, we assume the days he's wearing shirts he won't wear pants, and vise versa. Sure, Ergot would like that, but..

[iago]

10, I think?  That includes ones that are backwards-versions of other ones:

PPPII
PPIPI
PIPPI
IPPPI
PPIIP
PIPIP
IPPIP
PIIPP
IPIPP
IIPPP

[Newby]

That's a combination or permutation or some shit like that. :(

[Ender]

It's ten. The algebraic way of doing this (combinations) is 5! / (3!2!). There are 5! permutations and you have to divide by 3! because there are 3! arrangements of three purple balls in a row and 2! arrangements of the whatever-color ball in a row and those produce non-distinct permutations.

[Ergot]

It's ten. The algebraic way of doing this (combinations) is 5! / (3!2!). There are 5! permutations and you have to divide by 3! because there are 3! arrangements of three purple balls in a row and 2! arrangements of the whatever-color ball in a row and those produce non-distinct permutations.

OMG YOU'RE SO SMART x_x! I never learned that in algebra :(.

[Newby]

Hehe. I forgot everything I learned in pre-calc already. :(

[Joe]

I forgot how to figure premutations. :(

[Ender]

You forgot how to spell them, too.

[Chavo]

Either that or he really doesn't know how to recognize the factors preceding a mutation :P