Please answer quick please

A group of 8 friends (5 girls and 3 boys) plans to watch a movie, but they have only 5 tickets. If they randomly decide who will

Eddi Din [679]

Answer:

D. 0.821

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

The combinations formula is important to solve this question:

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

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

Desired outcomes

The order is not important. For example, Elisa, Laura and Roze is the same outcome as Roze, Elisa and Laura. This is why we use the combinations formula.

At least 3 girls.

3 girls

3 girls from a set of 5 and 2 boys from a set of 3. So

$C_{5,3}*C_{3,2} = 30$

4 girls

4 girls from a set of 5 and 1 boy from a set of 3. So

$C_{5,4}*C_{3,1} = 15$

5 girls

5 girls from a set of 5

$C_{5,5} = 1$

$D = 30+15+1 = 46$

Total outcomes

5 from a set of 8. So

$T = C_{8,5} = 56$

Probability

$P = \frac{D}{T} = \frac{46}{56} = 0.821$

So the correct answer is:

D. 0.821

6 0

2 years ago

Read 2 more answers

Explicit formula for an the nth term of the sequence 38,48,58

7nadin3 [17]

Answer:

10n + 28

Step-by-step explanation:

a + d (n-1)

a = 38

d = 10

38 + 10 (n-1)

38 + 10n -10

10n +38 - 10

10n + 28

Hope this helps!

3 0

2 years ago

City planners are planning to build a new community park. They agree that the park will be rectangular in shape, but the propose

podryga [215]

Answer:

(c) 714.96 = 21.6(w +4.7)

Step-by-step explanation:

The area of the rectangular park will be the product of its length and width. This relation is used to write an equation to find the original width of the park.

<h3>Width</h3>

Let w represent the original width of the park in meters. The new width is 4.7 meters more, so is represented by (w +4.7).

<h3>Other dimensions</h3>

The length of the park is given as 21.6 meters. The area is given as 714.96 square meters.

<h3>Area formula</h3>

The various dimensions of the park are related by the area formula:

A = LW

714.96 = 21.6(w +4.7)

4 0

1 year ago

Liz Williams claims to have psychic abilities and predict the future. Anderson Cooper, a CNN personality plans to test her in hi

Katena32 [7]

Answer:

b. Because the probability of being 15 or more correct is 0.0207, it is likely that she is just guessing at the questions.

Step-by-step explanation:

-This is a binomial probability distribution with p=0.5, n=20 and x=15.

The function is expressed as:

$P(X=x)={n\choose x}p^x(1-p)^{n-x}$

We calculate the probability of guessing 15 or more correctly:

$P(X\geq 15)=1-P(X$

The probability of passing, guessing 15+ correctly, is 0.0207. This probability is very low and it is it is likely that she is just guessing at the questions

7 0

2 years ago

Bob wants to create two pens, as shown in the figure. One pen is for a garden and it needs a heavy duty fence to keep out the cr

sattari [20]

$\bf \textit{the area of either pen is 2744, thus}\\\\
A=xy\implies 2744=xy\implies \cfrac{2744}{x}=y$

$\bf \begin{array}{llll}
\textit{perimeter of the garden pen}\\\\
P=2(x+y)\\\\
P=2\left( x+ \cfrac{2744}{x}\right)\\\\
P=2x+\cfrac{5488}{x}\\
----------\\

\textit{cost of it}\\\\
C=15\left( 2x+\cfrac{5488}{x} \right)\\\\
C=30x+\cfrac{82320}{x}
\end{array}\qquad 
\begin{array}{llll}
\textit{perimeter of the dog pen}\\\\
P=2x+y\\\\
P=2x+\cfrac{2744}{x}\\
----------\\
\textit{cost of it}\\\\
C=5\left( 2x+\cfrac{2744}{x} \right)\\\\
C=10x+\cfrac{27440}{x}
\end{array}$

notice... the dog's pen perimeter, does not include the side that's bordering the garden's, since that side will use the heavy duty fence, instead of the light one

so, the sum of both of those costs, will be the C(x)

$\bf C(x)=\left( 30x+\cfrac{82320}{x} \right)+\left( 10x+\cfrac{27440}{x} \right)
\\\\\\
C(x)=40x+\cfrac{109760}{x}$

so, just take the derivative of it, and set it to 0 to find the extremas, and do a first-derivative test for any minimum

8 0

3 years ago