Ask question

Ask question

All categories

3 years ago

13

You and six friends play a game where each person writes down his or her name on a scrap of paper, and the names are randomly di

stributed back to each person. Find the probability that everyone gets back his or her own name.

1 answer:

Vanyuwa [196]3 years ago

7 0

It would be 1/7 chance cause there are 7 people total but you have the 1 chance that you are going to get your own name

You might be interested in

What is the quotient in simplified form ? Need help please

Gre4nikov [31]

Answer:

$-\dfrac{4a^{12}b^8}{5}$

Step-by-step explanation:

The applicable rules of exponents are ...

$\dfrac{1}{a^{-b}}=a^b\\\\a^ba^c=a^{b+c}$

Your ratio simplifies to ...

$\dfrac{-8a^8b^{-2}}{10a^{-4}b^{-10}}=-\dfrac{4}{5}a^{8-(-4)}b^{-2-(-10)}\\\\=-\dfrac{4a^{12}b^8}{5}$

_____

Please note that simplifying the constants, -8/10 to -4/5, eliminates half the answer choices. Since exponents are only multiplied when a power is raised to a power, you can pretty much eliminate the second choice as being unreasonable. ((a^b)^c = a^(bc))

8 0

4 years ago

If one square yard costs 12 dollars how much is 180 square feet

Mumz [18]

12 x 180 is equal to 2160. It would cost $2160

3 0

3 years ago

Read 2 more answers

Fat Kat's offers a special on large two topping pizzas. In how many different ways can you order a two topping pizza if you can

Alexus [3.1K]

Answer:

in 9 different ways.

Step-by-step explanation:

divide 18 by 2 and u would get the answer

6 0

3 years ago

Read 2 more answers

Wetlands are important ecosystems for many reasons. Select all that apply.

OlgaM077 [116]

Answer:

A and B

Step-by-step explanation:

the bottom 2 don't make sense

7 0

3 years ago

A car insurance company has determined that 8% of all drivers were involved in a car accident last year. Among the 15 drivers li

svetlana [45]

Answer:

There is an 11.3% probability of getting 3 or more who were involved in a car accident last year.

Step-by-step explanation:

For each driver surveyed, there are only two possible outcomes. Either they were involved in a car accident last year, or they were not. This means that we solve this problem using binomial probability concepts.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.\pi^{x}.(1-\pi)^{n-x}$

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

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

And $\pi$ is the probability of X happening.

In this problem

15 drivers are randomly selected, so $n = 15$ .

A success consists in finding a driver that was involved in an accident. A car insurance company has determined that 8% of all drivers were involved in a car accident last year. This means that $\pi = 0.08$ .

What is the probability of getting 3 or more who were involved in a car accident last year?

This is $P(X \geq 3)$ .

Either less than 3 were involved in a car accident, or 3 or more were. Each one has it's probabilities. The sum of these probabilities is decimal 1. So:

$P(X < 3) + P(X \geq 3) = 1$

$P(X \geq 3) = 1 - P(X < 3)$

In which

$P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)$

$P(X = x) = C_{n,x}.\pi^{x}.(1-\pi)^{n-x}$

$P(X = 0) = C_{15,0}.(0.08)^{0}.(0.92)^{15} = 0.2863$

$P(X = 1) = C_{15,1}.(0.08)^{1}.(0.92)^{14} = 0.3734$

$P(X = 2) = C_{15,2}.(0.08)^{2}.(0.92)^{13} = 0.2273$

So

$P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2) = 0.2863 + 0.3734 + 0.2273 = 0.887$

Finally

$P(X \geq 3) = 1 - P(X < 3) = 1 - 0.887 = 0.113$

There is an 11.3% probability of getting 3 or more who were involved in a car accident last year.

5 0

3 years ago