Permutations and Combinations help

Totaling 14.In summary, the conversation is about a problem with question 9 where the correct answer is 14. The problem involves three different cases where the first person receives either 1 or 3 articles and the second person receives either 1 or 3 articles, and a third case where they both receive 2 articles. The correct answer is achieved by multiplying the permutations for each scenario and adding them together. The correctness of the answer depends on whether the articles are distinguishable or not.
  • #1
Ronaldo95163
77
1
Having problems with question 9 and what I came up was Case 1:
1st person gets 1 And
2nd person gets 3

OR

Case 2:
1st person gets 3 And
2nd person gets 1

OR

Case 3
They both get 2

And seeing that they are both dependent events so that once a person receives an article it affects the amount the next person gets. I used permutations for each of the two scenarios for each case, multiplied them and added them all together but I don't get the correct answer which is 14. What am I doing wrong?
 

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  • #2
Ronaldo95163 said:
Having problems with question 9 and what I came up wasCase 1:
1st person gets 1 And
2nd person gets 3

OR

Case 2:
1st person gets 3 And
2nd person gets 1

OR

Case 3
They both get 2

And seeing that they are both dependent events so that once a person receives an article it affects the amount the next person gets. I used permutations for each of the two scenarios for each case, multiplied them and added them all together but I don't get the correct answer which is 14. What am I doing wrong?
Are the articles supposed to be distinguishable? Do you reckon it matters?
 
  • #3
As long as the 4 articles are distinguishable, 14 is correct. Cases 1 and 2 have 4 possibilities each, while case 3 has 6.
 

FAQ: Permutations and Combinations help

What is the difference between permutations and combinations?

Permutations are arrangements of a set of objects where the order matters, while combinations are selections of objects where the order does not matter.

How do I know when to use permutations or combinations?

You should use permutations when the order of the objects is important, such as when arranging letters to form a word. Combinations should be used when the order is not important, such as selecting a group of people for a committee.

What is the formula for calculating permutations?

The formula for permutations is nPr = n! / (n - r)!, where n is the total number of objects and r is the number of objects being arranged.

What is the formula for calculating combinations?

The formula for combinations is nCr = n! / (r!(n-r)!), where n is the total number of objects and r is the number of objects being selected.

Can you give an example of permutations and combinations in real life?

An example of permutations would be the number of possible ways to arrange a deck of cards. An example of combinations would be the number of ways to choose a pizza with 3 toppings from a menu of 10 toppings.

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