If P(10,R) = 90, What Is R?

If p(10,r) = 90, what is r?

 

Answer:

r = 2

Step-by-step explanation:

P (n, r) = n!/(n-r)!

Given:

P(10,r) = 90

Where:

n =  10

r = Unknown

Solve for r:

10!/(10-r)! = 90

Cross-multiply:

10!/90 = (10-r)!

10×9×8×7×6×5×4×3×2×1/90  = (10-r)!

3,628,800/90 = (10-r)!

40,320 = (10 - r)!

8! = 10! - r!

r = 10 - 8

r = 2

Check:

P(10, 2) = 90

10!/(10-2)! = 90

10!/8! = 90

10 × 9 ×8×7×6×5×4×3×2×1/8×7×6×5×4×3×2×1 = 90

10 × 9 = 90

90 = 90  (True)


Comments

Post a Comment

Popular posts from this blog

The Grades In Mathematics Of The Students In Section A Are As Follows: 80, 75, 60, 95, 100. What Is The Populaton Mvariance Of Their Group?

Image
The grades in mathematics of the students in section A are as follows: 80, 75, 60, 95, 100. What is the populaton mvariance of their group?   Answer: The population variance is 206. Step-by-step explanation: Steps in solving for the population variance: 1) Find the mean by adding the values of (the grades in Math), then divide the sum by number of observations. Total Values (x): ∑x = (60 + 75 + 80 + 95 + 100) ∑x = 410 Population Mean: μ = ∑x/N    Where N = 5 μ =410/5 μ = 82 2) Subtract the mean from each x ⇒  (x - μ): 60 – 82 = - 22 75 – 82 = -7 80 – 82 = -2 95 – 82 = 13 95 – 82 = 18 3.) Square each difference between x and mean ⇒   (x - μ)²: (-22)2 = 484 (-7)2 = 49 (-2)2 = 4 (13)2 = 169 (18)2 = 324 4.) Add the results in #3: ∑(x - μ)² = (484 + 49 + 4 + 169 + 324) ∑(x - μ)² = 1,030 5.) Solve of the population variance (σ) by dividing the sum in #4 by the number of observations (N): Population Variance: σ² = ∑(x - μ)²  / N σ² = 1,030/5 σ² = 206 Please click the i
Read more

Ur Opinion For The Last Time

Image
Ur opinion for the last time   If I were to die today, I would make the most of it. I will do what I have always longed to do along with my family. I would create a legacy of my own, one which people will remember me by. I will go to those who are important to me and let them know how big the parts they play in my life. Most importantly and last but not the least, I will repent my sins, go to church and thank God for the life he had made me experience.
Read more

How Isa Information From The Dna Passed On From One Cell To Another

How isa information from the Dna passed on from one cell to another   Good Day Information in DNA will passed on from other cell via cell division. DNA is replicated in cell division and pass this replicated DNA to the daughter cells. This is how information in DNA transferred. There are two types of cell division in Human, mitosis and meiosis. Mitosis occur when one parent cell is divided to form 2 daughter cells both carrying 46 chromosomes. Meiosis is for the formation of sperm cell and egg cell which is said to be haploid carrying only 23 chromosomes. One parent cell is divided to form into 4 daughter cells.
Read more