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2 years ago

Tina must select and answer in any order three of seven

Mathematics

1 answer:

Leno4ka [110]2 years ago

6 0

Answer:

Tina can select and answer the essay questions on her test in 35 ways.

Step-by-step explanation:

The order in which she chooses the questions is not important. For example, choosing questions 1, 3 and 7 is the same as choosing 7, 3 and 1. So we use the combinations formula to solve this question.

Combinations formula:

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

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

In this question:

Three questions from a set of 7. So

$C_{7,3} = \frac{7!}{3!(7-4)!} = 35$

Tina can select and answer the essay questions on her test in 35 ways.

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Im really bad at math

densk [106]

Answer:

2.5

Step-by-step explanation:

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3 years ago

A survey was administered to high school seniors in Anytown. According to the survey results, fewer than 0.5% of the students dr

Feliz [49]

Answer: high test-retest reliability

Step-by-step explanation: this is because the result of the survey was thesame with the previous result, despite the space of time between when the first survey was conducted and when the second survey was conducted. There was know observable difference in result and if conducted in the next 3 months again, it will give same result, this strongly indicate that the survey has high test-retest reliability.

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2 years ago

Selena was comparing the flying speeds of different birds in science class. Which of the three birds flies fastest? Why?

Mashcka [7]

Answer:

Option C. The robin flies fastest because its rate is 15 m/s

Step-by-step explanation:

Let

x -----> the time in seconds

y ----> the distance in meters

The speed is equal to divide the distance by the time

In this problem, the slope or unit rate of the linear equation is the same that the speed

Robin's Flight

Find the slope

The formula to calculate the slope between two points is equal to

$m=\frac{y2-y1}{x2-x1}$

take two points from the table

(2,30) and (3,45)

substitute in the formula

$m=\frac{45-30}{3-2}$

$m=\frac{15}{1}$

$m=15\frac{m}{sec}$

Cardinal's Flight

$y=10x$

$m=10\frac{m}{sec}$

Blue Jay's Flight

take two points from the graph

(0,0) and (2,20)

substitute in the formula

$m=\frac{20-0}{2-0}$

$m=\frac{20}{2}$

$m=10\frac{m}{sec}$

Compare

The robin flies fastest because its rate is 15 m/s

4 0

3 years ago

Kevin says that “a line segment is the part of a line containing two endpoints.” What additional information is needed to make t

kakasveta [241]

The statement "That does not extend in both directions." will make the definition, precise.

Kevin's line segment definition is correct.

However, the end points in a line segment implies that the line segment does not extend past its two end points.

So, to make it precise;

Kevin needs to include that the line segment does not extend in both directions, in the definition.

Hence, option (c) is correct.

Read more about line segments at:

brainly.com/question/19203823

6 0

2 years ago

A manager must select three coders from her group to write three different software projects. There are 7 junior and 3 senior co

gavmur [86]

Answer:

The total number of ways are 168.

Step-by-step explanation:

Consider the provided information.

There are 7 junior and 3 senior coders in her group.

The first project can be written by any of the coders. The second project must be written by a senior person and the third project must be written by a junior person.

For second project we have 3 choices and for third project we have 7 choices.

Now there are 2 possible case:

Case I: If first and second coder is senior, then the total number of ways are:

$3\times 2\times 7=42$

Case II: If first and third coder is junior, then the total number of ways are:

$7\times 3\times 6=126$

Hence, the total number of ways are: 42+126=168

6 0

3 years ago