1. Good post? |

## permutation problem!

Q- In how many different ways can 5 boys and 4 girls sit togather in a row where boys and girls sit alternatly

ans:

B|G|B|G|B|G|B|G|B

5|4|4|3|3|2|2|1|1

5!*4! = 2880 arrangement

but if they sit like this

B|B|G|B|G|B|G|B|G
so,
5|4|4|3|3|2|2|1|1 (is it alternate way??)

so it's
5!*4! =2880 arrangement
so can anyone explain me is it the right ans............???
have i done silly mistake??

2. Good post? |
i think the only way boys/girls can sit alternately is to start the row with a boy, so total number of arrangements is 2880.

3. Good post? |
Originally Posted by ashraf Ali
Q- In how many different ways can 5 boys and 4 girls sit togather in a row where boys and girls sit alternatly

ans:

B|G|B|G|B|G|B|G|B

5|4|4|3|3|2|2|1|1

5!*4! = 2880 arrangement
Yes. You are right.
Originally Posted by ashraf Ali
B|B|G|B|G|B|G|B|G
so,
5|4|4|3|3|2|2|1|1 (is it alternate way?)
No

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