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1 year ago

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a math quiz consist of 30 questions. the first 20 questions are worth 4 points each. the last 10 questions are worth 7 points ea

ch. no points will be deducted for each wrong answer. Justin scores 124 points on a math quiz. how many of the first 20 questions and how many of the last 10 questions does he answer correctly?

2 answers:

never [62]1 year ago

3 0

Answer:

25

Step-by-step explanation:

Total points: (20x4) + (10x7) = 150

Justin scored 124/150

150-124 = ones he didn't get correct

150-124 = 26

26 = 4 + 7 + 4 +7 + 4

We are trying to figure out how many he answered <u>correctly</u> <em><u>NOT</u></em> how many he got wrong.

There are 30 questions. He got 5 wrong. That means he got 25 correct.

dedylja [7]1 year ago

3 0

Answer: He got 17 from the first 20questions and 8 from the last 10 questions

Step-by-step explanation:please see attachment for explanation

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Mrs.Steﬀen’s third grade class has 30 students in it. The students are divided into three groups(numbered 1, 2,and 3),each havin

qaws [65]

Answer:

a. $\\ 10! = 3628800$ ;

b. $\\ 10!*10!*10! = 47784725839872000000 = 4.7784725839872*10^{19}$

Step-by-step explanation:

We need here to apply the <em>Multiplication Principle </em>or the <em>Fundamental Principle of Counting</em> for each answer. Answer <em>b</em> needs an extra reasoning for being completed.

The <em>Multiplication Principle</em> states that if there are <em>n</em> ways of doing something and <em>m</em> ways of doing another thing, then there are <em>n</em> x <em>m</em> ways of doing both (<em>Rule of product</em> (2020), in Wikipedia).

<h3>In how many ways can ten students line up? </h3>

There are <em>ten</em> students. When one is selected, there is no other way to select it again. So, <em>no repetition</em> is allowed.

Then, in the beginning, there are 10 possibilities for 10 students; when one is selected, there are nine possibilities left. When another is selected, eight possibilities are left to form the file, and so on.

Thus, we need to multiply the possibilities after each selection: that is <em>why</em> the <em>Multiplication Principle</em> is important here.

This could be expressed mathematically using n!:

$\\ n! = n * (n-1)! * (n-2)! *...* 2*1.$

For instance, $\\ 5! = 5 * (5-1)! * (5-2)! *...*2*1 = 5 * 4 * 3 * 2 * 1 = 120.$

So, for the case in question, the <em>ten</em> students can line up in:

$\\ 10! = 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1 = 3628800$ ways to line up in a single file.

<h3>Second Question</h3>

For this question, we need to consider the former reasoning with extra consideration in mind.

The members of Group 1 can occupy <em>only</em> the following places in forming the file:

$\\ G1 = \{ 1, 4, 7, 10, 13, 16, 19, 22, 25, 28\}^{th}$ <em>places</em>.

The members of Group 2 <em>only</em>:

$\\ G2 = \{ 2, 5, 8, 11, 14, 17, 20, 23, 26, 29\}^{th}$ <em>places</em>.

And the members of Group 3, the following <em>only</em> ones:

$\\ G3 = \{ 3, 6, 9, 12, 15, 18, 21, 24, 27, 30\}^{th}$ <em>places.</em>

Well, having into account these possible places for each member of G1, G2 and G3, there are: <em>10! ways</em> for lining up members of G1; <em>10! ways</em> for lining up members of G2 and, also, <em>10! ways</em> for lining up members of G3.

After using the <em>Multiplication Principle</em>, we have, thus:

$\\ 10! * 10! * 10! = 47784725839872000000 = 4.7784725839872 *10^{19}$ <em>ways the students can line up to come in from recess</em>.

3 0

1 year ago

Paul is making turkey burgers that are 1/4 pounds each. he has 2.93 pound of turkeys

Vlada [557]

You can make about 11 burgers with that

5 0

1 year ago

Read 2 more answers

A study of 25 graduates of four-year public colleges revealed the mean amount owed by a student in student loans was $55,051. Th

Kitty [74]

Answer:

a

The 90% confidence interval is $52561.13 < \mu < 57540.8$

b

Confidence interval for the population men between <u>$52561.13</u> up to <u>$57540.8</u>

Step-by-step explanation:

From the question we are told that

The sample size is $n = 25$

The sample mean is $\= x = \$ 55,051$

The standard deviation is $\sigma = \$ 7,568$

Given that the confidence level is 90% then the level of confidence is mathematically represented as

$\alpha = 100 -90$

$\alpha = 10\%$

$\alpha = 0.10$

Next we obtain the critical value of $\frac{\alpha }{2}$ from the normal distribution table the values is

$Z_{\frac{\alpha }{2} } = 1.645$

Generally the margin of error is mathematically represented as

$E = Z_{\frac{ \alpha }{2} } * \frac{ \sigma }{\sqrt{n} }$

substituting values

$E = 1.645 * \frac{ 7568}{ \sqrt{ 25} }$

$E = 2489.9$

The 90% confidence interval is mathematically evaluated as

$\= x -E < \mu < \= x +E$

substituting values

$55051 - 2489.8 < \mu < 55051 + 2489.8$

$52561.13 < \mu < 57540.8$

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2 years ago

Square ABCD was translated using the rule (x, y) → (x – 4, y + 15) to form A'B'C'D'. What are the coordinates of point D in the

alisha [4.7K]

The translation is (x-4, y+15)

This means you would subtract 4 from the X coordinate and add 15 to the y coordinate.
The original coordinates is (9,-8)

The first number is X and the 2nd number is Y.

9-4 = 5

-8+15 = 7

The new location would be (5,7)

The answer is B.

4 0

1 year ago

Read 2 more answers

Kelly blends coffee. She mixes brand A costing $6 per kilogram with brand B costing $8 per kilogram. How many kilograms of each

sukhopar [10]

Step-by-step explanation:

Let

x

be the kg of coffee of brand A in the mix and

y

be the kg of coffee of brand B in the mix.

The total kg must be

50

.

x

+

y

=

50

The cost per kg of the mix must br

$

7.20

. For this, the total cost of the mix will be

6

x

+

8

y

, so the total cost per kg of the mix will be

6

x

+

8

y

50

.

6

x

+

8

y

50

=

7.20

Now that we have our two equations, we can solve.

6

x

+

8

y

=

7.20

⋅

50

6

x

+

8

y

=

360

From the first equation, we can multiply both sides by

6

to get:

6

x

+

6

y

=

300

Subtracting, we get:

2

y

=

60

y

=

30

Thus, we need

30

kg of brand B in our mix. This means that

50

−

30

=

20

kg will be of brand A.

6 0

1 year ago