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Setler79 [48]
3 years ago
12

What value is a permutation of n things taken r at a time divided by to get the combination of n things taken r at a time?

Mathematics
1 answer:
Lera25 [3.4K]3 years ago
5 0

Answer:

A. r!

Step-by-step explanation:

Combinations formula:

C_{n,x} is the number of different combinations of x objects from a set of n elements, given by the following formula.

C_{n,x} = \frac{n!}{x!(n-x)!}

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

P_{(n,x)} = \frac{n!}{(n-x)!}

Permutation of n things taken r at a time

P_{(n,r)} = \frac{n!}{(n-r)!}

Combination of n things taken r at a time:

C_{n,r} = \frac{n!}{r!(n-r)!}

Division:

\frac{P_{(n,r)}}{C_{n,r}} = \frac{\frac{n!}{(n-r)!}}{\frac{n!}{r!(n-r)!}} = \frac{n!}{(n-r)!} \times \frac{r!(n-r)!}{n!} = r!

So the correct answer is:

A. r!

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A man divided $9,000 among his wife, son, and daughter. The wife received twice as much as the daughter, and the son received $1
monitta

Answer:

Q1:

Share of the daughter (x):

2x + x + x + $1,000 = $9,000

4x = $8,000

x = $2,000

Share of the wife:

= 2($2,000)

=  $4,000

Share of the son:

= $2,000 + $1,000

= $3,000

Answer: wife, $4,000; son, $3,000; daughter, $2,000

Q2:

= 1/2x + $1,000

Answer: 1/2x + $1,000: expression for share of the son

Proof (the wife shares $4,000):

Share of wife (x):

x + 1/2x + 1/2x + $1,000 = $9,000

2x = $8,000

x = $4,000

Step-by-step explanation:

hope it helps!

6 0
3 years ago
Help please 10 points
irga5000 [103]

Answer:   it's the third one and the first one

Step-by-step explanation:

6 0
3 years ago
A.(7,8) <br> B.(2,22)<br> C.(2,8)<br> D.(3,29)
Law Incorporation [45]
Hey there!

To use the substitution method in order to solve the system of equations,
y=7x+8
y=x+20 , first notice that both equations are set equal to the same value, y.

Knowing this, 7x+8 and x+20 both equal the same value so you would set them equal to one another:
7x+8=x+20.

This would be substitution as you are substituting one of the equations in place of y.

Now, solve for x:
7x+8=x+20
6x+8=20
6x=12
x=2

Now that you know x equals the value of 2, you can substitute the value into one of the equations to find y:
y=x+20
y=2+20
y=22

Now that you have x=2 and y=22, you can conclude that your answer would be (2,22) or choice B.

Hope this helps and have a wonderful day! :)
7 0
3 years ago
What is 200 divided by 33?
castortr0y [4]
6.060606060606061 there you go
5 0
3 years ago
Read 2 more answers
What fraction was left of the candies? Don’t mind the work
mihalych1998 [28]

Answer:4/15

Step-by-step explanation:

2/5 = 6/15

1/3=5/15

6/15 +5/15= 11/15

15/15-11/15=4/15

4 0
3 years ago
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