Thread: Number of combinations

Hi,

I have this problem that i can't get right.

A team of 5 people are selected to participate in a chess tournament.
The "team" is picked within a school class with 17 boys and 13 girls. The rules state that the team must consist of at least 2 boys and 2 girls.

In how many ways can the team be selected?

So i thought this would be as simple as:

Either 2 boys and 3 girls or 3 boys and 2 girls.

[Math](17*16*15/3) * (13*12/2)*(13*12*11/3)*(17*16/2)[/tex]

That is incorrect though...

Any ideas on how to do this?

Originally Posted by Jones

Hi,

I have this problem that i can't get right.

A team of 5 people are selected to participate in a chess tournament.
The "team" is picked within a school class with 17 boys and 13 girls. The rules state that the team must consist of at least 2 boys and 2 girls.

In how many ways can the team be selected?

So i thought this would be as simple as:

Either 2 boys and 3 girls or 3 boys and 2 girls.



That is incorrect though...

Any ideas on how to do this?

2 boys and 3 girls:

3 boys and 2 girls:

Now add the two numbers together.

Originally Posted by Jones

A team of 5 people are selected to participate in a chess tournament. The "team" is picked within a school class with 17 boys and 13 girls. The rules state that the team must consist of at least 2 boys and 2 girls.

.
That choose three boys and two girls or two boys and three girls.

Originally Posted by Plato

.
That choose three boys and two girls or two boys and three girls.

A rare event - we both get the same answer (which means I've got a combinatorial question correct for once).

hah, it turned out to be really easy.

Did i make a twat out of myself?