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HACTEHA [7]
2 years ago
4

A DJ has a total of 1075 dance, rock, and country songs on her system. The dance selection is three times the size of the rock s

election. The country selection has 105 more songs than the rock selection. How many songs on the system are dance? rock? country?
All I need are the three equations.
Mathematics
2 answers:
Lelechka [254]2 years ago
3 0
D + R + C = 1075
D = 3R
C = R + 105
seraphim [82]2 years ago
3 0
Rock:
r
Country:
c=150+r
Dance:
d=3r

To get rock or the equation for rock you do 
150+r+3r+r= 1075

then combine like terms and use the inverse operations to get r isolated 

You might be interested in
The smallest natural number divisible by 2,3,4,5,6,8 and 9 is____.
SVETLANKA909090 [29]

Answer:

360

Step-by-step explanation:

You will need 2 * 2 * 2 for the smallest number to be divisible by 8 with all the others.

You will need 3 * 3  for the smallest number to be divisible by 9 with all the others.

Finally you will need 1 five

The smallest number divisible by all of these is 2*2*2*3*3*5 = 360

  • 360/2 = 180 works
  • 360/3 = 120 works
  • 360/5 = 72   works
  • 360/6 = 60 works
  • 360/8 = 45 works
  • 360/9 = 40 works.

There is no smaller number below 360 which will work.

7 0
2 years ago
A brewery produces cans of beer that are supposed to contain exactly 12 ounces. But owing to the inevitable variation in the fil
MArishka [77]

Answer:

T \sim N (\mu = 6*12=72 , \sigma= \sqrt{6} *0.3=0.735)

P(T \leq 72) = P(Z< \frac{72-72}{0.735}) = P(Z

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Solutio to the problem

Let X the random variable that represent the amount of beer in each can of a population, and for this case we know the distribution for X is given by:

X \sim N(12,0.3)  

Where \mu=12 and \sigma=0.3

For this case we select 6 cans and we are interested in the probability that the total would be less or equal than 72 ounces. So we need to find a distribution for the total.

The definition of sample mean is given by:

\bar X = \frac{\sum_{i=1}^n X_i}{n} = \frac{T}{n}

If we solve for the total T we got:

T= n \bar X

For this case then the expected value and variance are given by:

E(T) = n E(\bar X) =n \mu

Var(T) = n^2 Var(\bar X)= n^2 \frac{\sigma^2}{n}= n \sigma^2

And the deviation is just:

Sd(T) = \sqrt{n} \sigma

So then the distribution for the total would be also normal and given by:

T \sim N (\mu = 6*12=72 , \sigma= \sqrt{6} *0.3=0.735)

And we want this probability:

P(T\leq 72)

And we can use the z score formula given by:

z = \frac{x-\mu}{\sigma}

P(T \leq 72) = P(Z< \frac{72-72}{0.735}) = P(Z

6 0
2 years ago
A snowboarder leaves an 8-foot-tall ramp with an upward velocity of 28 feet per second. The function h   16t 2  28t 8 gives
mr_godi [17]

The complete question is;

A snowboarder leaves an 8-foot-tall ramp with an upward velocity of 28 feet per second. The function h = -16t² + 28t + 8 gives the height h (in feet) of the snowboarder after t seconds. The snowboarder earns 1 point per foot of the maximum height reached, 5 points per second in the air, and 25 points for a perfect landing. With a perfect landing, how many total points does the snowboarder receive?

Answer:

Total points earned with a perfect landing = 111 points

Step-by-step explanation:

First of all, let's find the maximum height of the given parabolic function h = -16t² + 28t + 8

h_max = c - (b²/4a)

where: a = -16, b = 28, c = 8

h_max = 8² - 28²/(4*(-16))

h_max = 64 + 784/64

h max = 76.25 ft ≈ 76 ft

The question says that the snowboarder earns 1 point per foot of the maximum height reached.

Thus, the points from the maximum height reached are 76 points

Now, let's find the maximum time in air by solving the equation for h = 0 Thus;

-16t² + 28t +8 = 0

Using quadratic formula,

t = [-28 ± √(28² - (4*-16*8))]/(2*-16)

t = 2 or -0.25

We'll use 2 as we are looking for maximum time.

The question says at maximum time, it's 5 points for each second in the air,

thus, points for seconds in air = 5 × 2 = 10 points

We are told 25 points for perfect landing.

Thus,

Total points earned with a perfect landing = 76 + 10 + 25 = 111 points

7 0
2 years ago
Marcella ate one cup of air popped popcorn. which equation can Marcelo use to find how many carbohydrates she consumed?
Dahasolnce [82]
She ate 6.2 carbohydrates

8 0
2 years ago
Read 2 more answers
The double number line shows that 444 bottles of water cost 101010 dollars at a music festival. Based on the ratio shown in the
MrRissso [65]

Answer:

Please see the attachment for double number line.

Explanation:

We are given cost of 4 water bottles is $10

We can write ,

Cost of 4 bottles = $10

Cost of 1 bottle = $2.5

Cost of 2 bottles =$5

Cost of 3 bottles = 3\times 2.5 = $7.5

Cost of n bottles = $2.5n

Now we draw the double number line.

Bottom line(Line 1)  will take as number of bottles:  

1   2   3   4   5   6  

Above line (Line 2) will show the cost of corresponding number of bottles:

2.5  5  7.5  10  12.5  15  


 


4 0
2 years ago
Read 2 more answers
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