How do u solve for n Permutations

In summary, the conversation discusses how to solve for n in the equation nP3=720 by using the factor theorem. The solution is found by expanding and factoring out 720 from the left side of the equation. It is also suggested to factor 720 into smaller numbers such as 24, 32, and 5 to help find the solution.
  • #1
gillgill
128
0
how do u solve for n?
nP3=720...n!/(n-3)!=720...do u just start cancelling?
that will be n(n-1)(n-2)=720...but its such a big number...is there another easier way to do it?
 
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  • #2
gillgill said:
how do u solve for n?
nP3=720...n!/(n-3)!=720...do u just start cancelling?
that will be n(n-1)(n-2)=720...but its such a big number...is there another easier way to do it?
SOLUTION HINTS:
Factor 720 to help find the solution:
720 = (24)*(32)*(5) = n*(n - 1)*(n - 2) = (?)*(?)*(?)
(Hint: Try 23)


~~
 
Last edited:
  • #3
gillgill said:
how do u solve for n?
nP3=720...n!/(n-3)!=720...do u just start cancelling?
that will be n(n-1)(n-2)=720...but its such a big number...is there another easier way to do it?

by cancelling do you mean use the factor theorem? because i would expand and move the 720 to the left side and factor it out
 

Related to How do u solve for n Permutations

1. What is the formula for solving n permutations?

The formula for solving n permutations is n! (n factorial).

2. How do I determine the value of n in a permutation problem?

The value of n in a permutation problem represents the number of objects or items being arranged. It can be found in the given problem or can be determined by counting the number of items in a set.

3. Can n be a decimal or negative number in a permutation problem?

In most cases, n is a positive integer in a permutation problem. However, in some cases, n can be a decimal or negative number, depending on the context of the problem. It is important to carefully read and understand the problem before determining the value of n.

4. How do I solve for n permutations when there are repeated items?

When there are repeated items in a permutation problem, the formula for solving n permutations changes to n! / (n1! * n2! * ... * nr!), where n1, n2, ..., nr represent the number of repetitions for each item. For example, if there are 3 A's, 2 B's, and 1 C, the formula would be n! / (3! * 2! * 1!).

5. Can I use a calculator to solve for n permutations?

Yes, you can use a calculator to solve for n permutations. However, it is important to make sure that your calculator has a factorial function and to use parentheses correctly when entering the formula. Alternatively, you can use a permutation calculator or a permutation formula table to find the solution.

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