Please answer correctly!! I’ll mark as brainliest! No links no fake answers

Of the 9-letter passwords formed by rearranging the letters AAAABBCCC (4 A's, 2 B's, and 3 C's), I select one at random. Determi

Tanya [424]

Answer:

a) 3

b) (8!/9!)-(7!/9!)

c) (1-(8!/9!))*(7!/9!)

Step-by-step explanation:

a)With 4 As ; 2Bs and 3Cs it is possible to get a palindrome if you fixed the letters C according to: (2) in the extremes of the word and the other one at the center therefore you only have palindrome in the following cases

C ( ) C ( ) C

To fill in the gaps we have 4 letters A and 2 letters B, wich we have two divide in two palindrome gaps,

AAB and BAA the palindrome is C AAB C BAA C

BAA and AAB " " is C BAA C AAB C

ABA and ABA " " is C ABA C ABA C

b) 4 A ; 2B ; 3C

We have the total number of elements 9, so the total number of possible outcomes is : 9!

Total events: 9!

if we fixed 3 C we have (the group of 3 Cs becoming one element) so the total amount of events with 3 adjacent Cs is: 7!

Therefore the probability of having 3 adjacent Cs is: 7!/9!

If we fixed only 2 Cs we have:

4 A ; 2 B ; 2C : 1C

Total number of words (events) in this case is 8! (2C becomes 1 element)

so the total numbers of events is 8! the probability in this case is 8!/9!(this value includes cases of adjacent 3 Cs previous calculated ) so this value minus the case of 3 adjacent Cs ) give us 2 adjacent C and the other no next to them

Probability (of words with 2 adjacent Cs and the other no next to them is); 8!/9! - 7!/9!

c) Probability of B apart from each other is the whole set of events minus those where 2 B are adjacent or (become 1 element)

4 A ; 2B ; 3C

Total of events 9! and events with adjacent B is 8!/9!

Therefore the probability of words with 3 adjacent Cs and 2 B separeted is

the probability of 3 adjacent Cs (7!/9!) times probability of words with no adjacent Bs wich is (1-(8!/9!))*(7!/9!)

5 0

3 years ago

helppppppppp??????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!????!>>>>>>>>>>>>>>&g

e-lub [12.9K]

Answer:

-(m-6)=3m+14

-m+6=3m+14

I would appreciate if my answer is chosen as a brainliest answer

6 0

2 years ago

Question 15 (5 points) Find the angle between u = <7, -2> and v= (-1,2>.

Tema [17]

Answer:

Approximately $2.3127$ radians, which is approximately $132.51^{\circ}$ .

Step-by-step explanation:

Dot product between the two vectors:

$\begin{aligned}& u\cdot v \\ =\; & 7 \times (-1) + (-2) \times 2 \\ =\; & (-11) \end{aligned}$ .

Magnitude of the two vectors:

$\begin{aligned} \| u \| &= \sqrt{{7}^{2} + {(-2)}^{2}} \\ &= \sqrt{53} \end{aligned}$ .

$\begin{aligned} \| v \| &= \sqrt{{(-1)}^{2} + {2}^{2}} \\ &= \sqrt{5} \end{aligned}$ .

Let $\theta$ denote the angle between these two vectors. By the property of dot products:

$\begin{aligned} \cos(\theta) &= \frac{u \cdot v}{\|u\| \, \| v \|} \\ &= \frac{(-11)}{(\sqrt{53})\, (\sqrt{5})} \\ &= \frac{(-11)}{\sqrt{265}}\end{aligned}$ .

Apply the inverse cosine function ${\rm arccos}$ to find the value of this angle:

$\begin{aligned} \theta &= \arccos\left(\frac{u \cdot v}{\| u \| \, \| v \|}\right) \\ &= \arccos\left(\frac{(-11)}{\sqrt{265}}\right) \\ & \approx \text{$2.3127$ radians} \\ &= 2.3127 \times \frac{180^{\circ}}{\pi} \\ &\approx 132.51^{\circ}\end{aligned}$ .

8 0

2 years ago

Which of the following circles have their centers on the x-axis? Check all that apply.

Alexeev081 [22]

Answer: Option A and Option D

Step-by-step explanation:

By definition the general equation of a circle has the following form

$(x-h)^2+ (y-k)^2=r^2$

Where r is the radius and the point (h, k) is the center of the circle

All points that are on the x axis have the following form:

(h, 0)

Therefore all the circles that have their centers on the x axis will have a value of k = 0.

Identify among the options all those equations that have a value of k = 0

The circles that have their center on the x axis are option A and option D

7 0

3 years ago

There are 4 sharks and 5 dolphins. Write the ratio of sharks to dolphins. Then find and interpret the value of the ratio.

Anna35 [415]

Answer:

here is the ratio 1 : 1.25 (sharks: dolphins)

Step-by-step explanation:

8 0

2 years ago