The cost of 3 DVD's and 4 CD's is £62.00. The cost of 4 DVD's and 3 CD's is £64.00. Find the cost of each.
Help!!!

Answer:

25 questions,

$18.75

Step-by-step explanation:

Remember, to change percents to decimals, divide the number by 100 and remove the parentheses.

1. 84%, or 21 questions of Roy's test were correct.

Let's set the number of questions on the test as "x". We can then write this equation:

84% * x = 21

Simplify.

0.84 * x = 21

Divide both sides by 0.84

x = 25

There were 25 questions on the test.

2. Cheesecake Factory question

We need to find 15% of 125.

15% * 125 =

0.15 * 125 =

18.75

They need to leave a $18.75 tip.

I hope this helps! Feel free to ask any questions!

Answer:

22 feet below sea level

Step-by-step explanation:

she kept going down, basically in a negative way. adding to the already below sea level

Answer:

C. 20 Ft.

Step-by-step explanation:

Using The Pythagorean Theorem, a²+b²=c² , insert the known variables into the equation.

18.7²+6²=c²

This gives you 385.69 + 36 = 385.69.

Next, square the result to find the missing side length.

[tex]\sqrt{385.69[/tex]

The answer comes out to around 19.6, which can be rounded up to 20ft.

Hope this helped!

Answer:

df(t)/dt = 10 - 0.8f(t)

Step-by-step explanation:

The net rate of change, df(t)/dt = rate in - rate out

The rate in = rate litter forms on ground = 10 g/cm²/yr

Since f(t) is the amount of litter present at time, t, in g/cm² the rate out = rate of decomposition = the percentage rate × f(t) = 80% per year × f(t) = 0.8f(t) g/cm²/yr

Since df(t)/dt = rate in - rate out

df(t)/dt = 10 - 0.8f(t)

So the desired differential equation is

df(t)/dt = 10 - 0.8f(t)

Answer:

Jacob had more home runs relative to his usual season average than Hugo did.

Step-by-step explanation:

The key solving this is to express their respective home runs in z-value forms.

Z = (x - ų)/óx

X = Current home runs

Ų = Mean

= Meanóx = Standard deviation

For Hugo,

X = Current home run = 31

Ų = Mean = 27

Óx = Stardard deviation = 1.6

Z = (x - ų)/óx

Z = (31 - 27)/1.6 = 2.5

Hope this helped!!!

The person who had more home runs relative to their usual seasonal average was Jacob.

Representing their home runs in z-value forms.

Where

= Meanóx = Standard deviation

To find the home run for Hugo,

Therefore,

Z = (x - ų)/óx

Z = (31 - 27)/1.6

= 2.5

Hence, Jacob had the most home runs relative to their usual seasonal average.

Read more about standard deviation here:

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Answer:

The standard error of the difference in the mean number of fish caught before and after the fire is 0.2153.

Step-by-step explanation:

Subtraction of normal variables:

When we subtract two normal variables, the standard deviation is the square root of the sum of variances of each variable.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Sample of 195 fishing reports before the fire, the mean catch was 6.3 fish with a standard deviation of 1.6.

The standard error for this sample is:

[tex]s_b = \frac{1.6}{\sqrt{195}} = 0.1246[/tex]

Sample of 143 reports three years after the fire, the mean catch was 7.1 fish with a standard deviation of 2.1.

The standard deviation for this sample is:

[tex]s_a = \frac{2.1}{\sqrt{143}} = 0.1756[/tex]

What represents the standard error of the difference in the mean number of fish caught before and after the fire?

[tex]s = \sqrt{s_a^2 + s_b^2} = \sqrt{0.1756^2 + 0.1246^2} = 0.2153[/tex]

The standard error of the difference in the mean number of fish caught before and after the fire is 0.2153.

Answer:

sqrt [ (1.6^2)/195 + (2.1^2)/143 ]

Answer:

The rate increases at 398mi/h

Step-by-step explanation:

Given

[tex]\frac{dx}{dt} = 460mi/h[/tex] --- rate when [tex]y = 2[/tex] --- distance

The given parameters is represented with the attached figure

Using Pythagoras theorem [take the attached image as a point of reference]

[tex]y^2 = x^2 + 1^2[/tex]

[tex]y^2 = x^2 + 1[/tex]

Differentiate with respect to time (t):

[tex]2y \frac{dy}{dt} = 2x \frac{dx}{dt}[/tex]

Divide both sides by 2

[tex]y \frac{dy}{dt} = x \frac{dx}{dt}[/tex] --- (1)

When y = 2:

[tex]y^2 = x^2 + 1^2[/tex] --- Pythagoras Theorem

[tex]2^2 = x^2 + 1[/tex]

[tex]4 = x^2 + 1[/tex]

Collect like terms

[tex]x^2 = 4 -1[/tex]

[tex]x^2 = 3[/tex]

Solve for x

[tex]x = \sqrt 3[/tex]

So:

[tex]y \frac{dy}{dt} = x \frac{dx}{dt}[/tex]

Substitute: [tex]x = \sqrt 3[/tex], [tex]\frac{dx}{dt} = 460mi/h[/tex] and [tex]y = 2[/tex]

[tex]2 * \frac{dy}{dt} = \sqrt 3 * 460[/tex]

[tex]2 * \frac{dy}{dt} = 460\sqrt 3[/tex]

Divide by 2

[tex]\frac{dy}{dt} = 230\sqrt 3[/tex]

[tex]\frac{dy}{dt} = 230*1.7321[/tex]

[tex]\frac{dy}{dt} = 398.383[/tex]

[tex]\frac{dy}{dt} \approx 398[/tex]

3, and apparently its "too short of an answer on this website"

Answer:

5 batches per hour

Step-by-step explanation:

Answer:

3) Obtuse

4) Right

Step-by-step explanation:

3)

11 + 13 > 25 It is a triangle

11² + 13² = 25²

121 + 169 = 625

290 ≠ 625

Since hypotenuse is larger, the triangle is obtuse

4)

21 + 28 > 35 It is a triangle

21² + 28² = 35²

441 + 784 = 1225

1225 = 1225

Since the hypotenuse is equal to the legs, it's a Right triangle

Answer:

A

Step-by-step explanation:

its a bec count how many student are their an see if they add IP to 30

The Venn diagram which shows the number of students who play basketball and baseball is option A.

Venn diagram is a diagram denoting two or more sets which is drawn using circles inside a rectangle where the part where the two circle meet denotes the intersection of two sets.

Let A denotes the students playing baseball and B denotes the student playing basketball.

N(A) = 18

N(B) = 17

N(A ∪ B) = 30

We know,

N(A ∩ B) = N(A) + N(B) - N(A ∪ B)

              = 18 + 17 - 30

              = 35 - 30

              = 5

Number of students who play both baseball and basketball = 5

Number of students who plays only baseball = 18 - 5 = 13

Number of students who plays only basketball = 17 - 5 = 12

This is shown in A.

Hence the correct option is A.

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Answer:    send group

Step-by-step explanation:

Answer:

Step-by-step explanation:

Answer:

Step-by-step explanation:

If the 2 is an exponent, it needs to be written as ^2.

(5+√3)²  = 5² + 10√3 + 3 = 28 + 10√3

Answer:

the answer is d

Step-by-step explanation:

Answer:

No, it is not a solution

Step-by-step explanation:

Given

[tex]x - y = 4[/tex]

[tex]2x + y = 5[/tex]

Required

Is (4,3) a solution?

(4,3) implies that: [tex]x = 4\ y =3[/tex]

So:

[tex]x - y = 4[/tex]

[tex]4 - 3 = 4[/tex]

[tex]1 \ne 4[/tex]

Because 1 and 4 are not equal, then (4,3) is not a solution

Answer:

x=-2 and y =0

Step-by-step explanation:

2x + 3y=-4

y=2x + 4

2x -y = -4

4y= 0

y = 0

2x -0=-4

2x =-4

x=-2

Answer:

9(3+c+4)=

27+9c+36=

63+9c=

Step-by-step explanation:

9(3+c+4)=

27+9c+36=

63+9c=

Answer:

The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! A variable doesn't have to be "x", it could be "y", "w" or any letter, name or symbol.

Step-by-step explanation:

Answer: 803mm

Step-by-step explanation:

The solution is, 0.39 = 39% of probability.

Probability can be defined as the ratio of the number of favorable outcomes to the total number of outcomes of an event.

here, we have,

When you need to calculate probabilities involving "or" questions, in general you should use the following formula: , where P(A) is the probability of event A and P(B) is the probability of event B.

In the problem given, P(A) = yes and P(B) = male, then:

P(yes) = 33/100

          = 0.33

P(male) = 20/100

            = 0.20 (all male that answered the question)

P(yes and male)

= 14/100

= 0.14 (all male that answered yes to the question)

P(yes or male) = P(yes) + P(male) - P(yes and male)

                        = 0.33+0.20-0.14

                        = 0.39

                        =39%

Hence, The solution is, 0.39 = 39% of probability.

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Complete question:

One hundred people were asked, "Do you favor the death penalty?" Of the 33 that answered "yes" to the question, 14 were male. Of the 67 that answered "no" to the question, six were male. If one person is selected at random, what is the probability that this person answered "yes" or was a male?

Answer:

x = 1.2

Step-by-step explanation:

AD/AB = DE/BC (Similarity Theorem)

AD = 6 + 4 = 10

AB = 6

DE = 2

BC = x

Plug in the values

10/6 = 2/x

Cross multiply

10*x = 2*6

10x = 12

Divide both sides by 10

x = 12/10

x = 1.2

Answer:

B. 40 meters

Step-by-step explanation:

there are 100 cm in a meter

we can divide 4,000 by 100 to see how many meters are equivalent to 4,000 cm.

4,000/100 = 40

Therefore, the answer is B. 40 meters

hope this helps :)

Answer:

d

Step-by-step explanation:

60x9 =540

Answer:

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