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3 years ago

A shelf holds 27 books of which 6 are textbooks, 12 are fiction and 9 are biographies. 5 of the books are selected randomly.

Mathematics

1 answer:

ladessa [460]3 years ago

3 0

Answer:

1) (12C1×15C4)/(27C5)

= 14/69 or 0.2029

2) (6C1×12C2×9C2)/(27C5)

= 264/1495 or 0.1766

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Alexander is going to buy a stereo from his older brother with $93 he will pay him an equal amount of money each month for 12 mo

jenyasd209 [6]

Your answer would be B.

Step-by-step explanation:

$93 / 12 = $7.75

7 0

4 years ago

Two cars simultaneously left Points A and B and headed towards each other, and met after 2 hours and 45 minutes. The distance be

zheka24 [161]

<h2>Hello!</h2>

The answer is:

$FirstCarSpeed=41mph\\SecondCarSpeed=55mph$

To calculate the speed of the cars, we need to write two equations in order to create a relation between the two speeds and be able to isolate one in function of the other.

So, let be the first car speed "x" and the second car speed "y", writing the equations we have:

For the first car:

$x_{FirstCar}=x_o+v*t$

For the second car:

We know that the speed of the second car is the speed of the first car plus 14 mph, so:

$x_{SecondCar}=x_o+(v+14mph)*t$

Now, we already know that both cars met after 2 hours and 45 minutes, meaning that positions will be the same at that moment, and the distance between A and B is 264 miles, so, we can calculate the relative speed between them:

If the cars are moving towards each other the relative speed will be:

$RelativeSpeed=FirstCarSpeed-(-SecondCarspeed)\\\\RelativeSpeed=x-(-x-14mph)=2x+14mph$

Then, since we know that they covered a combined distance which is equal to 264 miles of distance in 2 hours + 45 minutes, we have:

$2hours+45minutes=120minutes+45minutes=165minutes\\\\\frac{165minutes*1hour}{60minutes}=2.75hours$

Writing the equation, we have:

$264miles=(2x+14mph)*t\\\\264miles=(2x+14mph)*2.75hours\\\\2x+14mph=\frac{264miles}{2.75hours}\\\\2x=96mph-14mph\\\\x=\frac{82mph}{2}=41mph$

We have that the speed of the first car is equal to 41 mph.

Now, for the second car we have that:

$SecondCarSpeed=FirstCarSpeed+14mph\\\\SecondCarSpeed=41mph+14mph=55mph$

Hence, we have that:

$FirstCarSpeed=41mph\\SecondCarSpeed=55mph$

Have a nice day!

4 0

3 years ago

Read 2 more answers

X/2-7 is rational algebra expression or irrational?

goldfiish [28.3K]

Answer:

I think it's rational number

3 0

3 years ago

Number of graduates: suppose 75% of the graduating class in a certain high school goes on to college. if 270 students from this

professor190 [17]

270 x 0.75 = 202.5 students, so say 203 students

6 0

3 years ago

Questions attached below ( *︾▽︾) Thanks for the help :)

german

Answer:

See below

Step-by-step explanation:

Attachment 1 : (a) Remember that it mentions x is the years since 1900. That would mean that the table is a bit different. To create this " new table " simply subtract 1900 from the years provided, and substitute.

To create this equation we will need a regression calculator. The equation will be as follows.

y = 0.125873x - 7.11916 ( note that you can double check this equation be substituting points from the table in the attachment )

(b) 2025 - 1900 = 126 years,

y = 0.125873(125) - 7.11916 = $ 8.614965

Minimum Wage : $ 8.614965

Attachment 2 : The rest of the problems can be solved similarly...

(a) Quadratic Regression Equation : - 0.49311x² + 23.2798x + 996.029

(b) - 0.49311(20)² + 23.2798(20) + 996.029 = 1264.381 mg/cm³

Attachment 3 : (a) Exponential Regression : 9.08292(1.09965)ˣ

(b) 9.08292(1.09965)⁶⁰ = $2713.27743\dots$ ( About 2713 recommendations )

8 0

4 years ago