# lost

• Nov 18th 2006, 02:06 AM
scrappy
lost
how many ways can we arrange a row of four girls followed by four boys if girls must sit togther and boys must sit together?

i know stuiped question i just cant figure it out lol
• Nov 18th 2006, 03:37 AM
Soroban
Hello, scrappy!

Quote:

How many ways can we arrange a row of four girls followed by four boys
if girls must sit togther and boys must sit together?

. . $\displaystyle \underbrace{G\:G\:G\:G}_{\text{4! ways}}\,\underbrace{B\:B\:B\:B}_{\text{4! ways}}$

Answer: .$\displaystyle 4! \times 4! \:=\:24 \times 24 \:= \:576$ ways

• Nov 18th 2006, 07:56 AM
CaptainBlack
Quote:

Originally Posted by Soroban
Hello, scrappy!

. . $\displaystyle \underbrace{G\:G\:G\:G}_{\text{4! ways}}\,\underbrace{B\:B\:B\:B}_{\text{4! ways}}$

Answer: .$\displaystyle 4! \times 4! \:=\:24 \times 24 \:= \:576$ ways

What happened to $\displaystyle BBBBGGGG$?

which doubles the number of ways.

RonL
• Nov 18th 2006, 10:21 AM
Soroban
Quote:

Originally Posted by CaptainBlack
What happened to $\displaystyle BBBBGGGG$?

It's a matter of interpretation, I guess, but I did give it some thought.

"How many ways can we arrange a row of four girls followed by four boys . . . "
. . I read that to mean in that order.

If they meant $\displaystyle GGGGBBBB$ or $\displaystyle BBBBGGGG$, why use the phrase "followed by"?

Wouldn't it have said, "In how many ways can we arrange a row of four girls and four boys
. . if girls must sit togther and boys must sit together?"

• Nov 18th 2006, 10:43 AM
CaptainBlack
Quote:

Originally Posted by Soroban
It's a matter of interpretation, I guess, but I did give it some thought.

"How many ways can we arrange a row of four girls followed by four boys . . . "
. . I read that to mean in that order.

If they meant $\displaystyle GGGGBBBB$ or $\displaystyle BBBBGGGG$, why use the phrase "followed by"?

Wouldn't it have said, "In how many ways can we arrange a row of four girls and four boys
. . if girls must sit togther and boys must sit together?"

Yes, I guess that your interpretation fits the question better than mine,
must resolve to read the questions more carefully for the rest of the day:(

RonL