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ziro4ka [17]
3 years ago
5

) An instructor gives his class a set of 18 problems with the information that the next quiz will consist of a random selection

of 9 of them. If a student has figured out how to do 13 of the problems, what is the probability the he or she will answer correctly
Mathematics
1 answer:
RSB [31]3 years ago
3 0

Answer:

The probability the he or she will answer correctly is 1.5%

Step-by-step explanation:

In all, there are 18 problems. In this question, the order of which the problems are sorted for the quiz makes no difference. For example, if the question A of the quiz is P1 and question B P2, and question A P2 and question B P1, it is the same thing.

There are 18 problems and 9 are going to be selected. So, there is going to be a combination of 9 elements from a set of 18 elements.

A combination of n elements from a set of m objects has the following formula:

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

In this question, m = 18, n = 9. So the total number of possibilities is:

T_{p} = C_{(18,9)} = \frac{18!}{9!(18-9)!} = 48620

Now we have to calculate the number of desired outcomes. This number is a combination of 9 elements from a set of 13 elements(13 is the number of problems that the student has figured out how to do).

Now, m = 13, n = 9. The number of desired possibilities is:

D_{p} = C_{(13,9)} = \frac{13!}{9!(13-9)!} = 715

The probability is the number of desired possibilities divided by the number of total possibilities. So

P = \frac{715}{48620} = 0.015 = 1.5%

The probability the he or she will answer correctly is 1.5%

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Answer:

T F F F T F T

Step-by-step explanation:

A 2D vector can have a component equal to zero even when its magnitude is nonzero. TRUE.

it will be actually a 1d vector, but it's still a 2d vector too. this happens when the vector it's aligned to one of the axis.

The direction of a vector can be different in different coordinate systems. FALSE

The direction of a vector is independent of any coordinate system.

A 2D vector can have a magnitude equal to zero even when one of its components it nonzero. FALSE.

because the only way \sqrt{x^{2} +y^{2} } =0 is that both x and y are equal to zero

The magnitude of a vector can be different in different coordinate systems. FALSE.

The magnitude stays the same in every coordinate system

It is possible to multiply a vector by a scalar. TRUE.

it changes only it's magnitude.

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The components of a vector can be different in different coordinate systems.TRUE.

The components of a vector are just a way for identifying the vector, in a determinate coordinate system, the way i call those components will change as I change the name I call every point in the plane.

5 0
3 years ago
1 7/8 divided by 2 8/11
Bingel [31]

Answer: 11/16

<u>Turn 1 7/8 into an Improper Fraction</u>

Multiply 1×8 and get 8. Now add 7 and get 15.

1 7/8 = 15/8

<u>Turn 2 8/11 into an Improper Fraction</u>

Multiply 2×11 and get 22. Now add 8 and get 30.

2 8/11 = 30/11

<u>Do Keep Change Flip</u>

Keep: 15/8

Change ÷ into ×

Flip: 30/11 into 11/30

Your New Problem: 15/8×11/30

<u>Multiply</u>

15/8×11/30=165/240

<u>Simplify</u>

165/240÷15/15=11/16

3 0
3 years ago
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bezimeni [28]
20(24) = 480 items per day
480(30) = 14,400 items per month

7 0
3 years ago
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Strike441 [17]
X is less than or equal to -1.5
3 0
3 years ago
The soulution to 6+2x&gt;32 is either x&gt;13 or x&lt;13. Which soulution is correct? Explain how you know - prove it with a num
hjlf

Answer:

6+2x >32

2x>32-6

2x>26

divide both sides by 2

therefore, x>13

Step-by-step explanation:

this is because x don't has a negative sign or is on the other side

4 0
1 year ago
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