James ruse 03 trial perm question (1 Viewer)

[Li0n]

Here's my solution: (btw, what exactly does "by inspecion" mean?)

Let C denote a consonant and V a vowel. First lay out the Cs:

C C C C C C C

There are now 8 gaps for the Vs, and since there are 4 Vs there are 8C4 ways of distributing the 4 Vs into the 8 gaps. So if all the Cs were identical and all the Vs were identical, there would be 8C4 ways of arranging them. But since there are 7 consonants, with 2 pairs being identical, there are 7!/(2!*2!) ways of arranging them, and since the two E's are indistinguishable, there is 1 way of arranging the vowels. So the answer is:

8C4*7!/(2!*2!)*1 = 88200

*hugs*

i thought inspection also meant writing out all the possible combinations, in your head though...

 

[mojako]

how do you write 88200 combinations in your head?

 

[withoutaface]

*hugs*

i thought inspection also meant writing out all the possible combinations, in your head though...

Hahahaha you hugged a guy!

 

[Li0n]

how do you write 88200 combinations in your head?

you dont write them down. You calculate them eg, 7! in calculator, write down the answers of the combinations one by one, then add up all the way.

withoutaface, you sound like a lonely little boy

 

[Archman]

withoutaface, you sound like a lonely little boy

getting a face might help