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blackops23

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There are 4 identical red marbles, 3 identical yellow marbles and 2 identical green marbles arranged in a row.

(i) How many different arrangements of just 5 marbles are possible if all 3 colours must be included?

Can someone please explain how to do this with copious amounts of detail lol?

So far I've got:

3R 1Y 1G
2R 1Y 2G
2R 2Y 1G
1R 1Y 3G
1R 3Y 1G
1R 2Y 2G

^these are the ways you can do the selection. But now what do you do?

Thanks appreciate the help
 

MATHSCAPE

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There are 4 identical red marbles, 3 identical yellow marbles and 2 identical green marbles arranged in a row.

(i) How many different arrangements of just 5 marbles are possible if all 3 colours must be included?

Can someone please explain how to do this with copious amounts of detail lol?

So far I've got:

3R 1Y 1G
2R 1Y 2G
2R 2Y 1G
1R 1Y 3G
1R 3Y 1G
1R 2Y 2G

^these are the ways you can do the selection. But now what do you do?

Thanks appreciate the help
can't have that.

what's the answer btw?
 
Last edited:

math man

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There are 4 identical red marbles, 3 identical yellow marbles and 2 identical green marbles arranged in a row.

(i) How many different arrangements of just 5 marbles are possible if all 3 colours must be included?

Can someone please explain how to do this with copious amounts of detail lol?

So far I've got:

3R 1Y 1G
2R 1Y 2G
2R 2Y 1G
1R 1Y 3G
1R 3Y 1G
1R 2Y 2G

^these are the ways you can do the selection. But now what do you do?

Thanks appreciate the help
well with these possibilities...you work out how many ways you can have each:

3R 1Y 1G can be arranged in: ways to count for the repetition of the 3 R's.

2R 1Y 2G can be arranged in: ways to count for the repetition of the 2R's and G's

Now you repeat this for every situation you can have then add each as these are 'or' cases.
 

MATHSCAPE

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you've got all the different combinations, just do what math man said and you should get it.
 

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