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Gala2k [10]
3 years ago
12

Christine purchased a prepaid phone card for $20. Long distance calls cost 18 cents a minute using this card. Christine used her

card only once to make a long distance call. If the remaining credit on her card is $15.68, how many minutes did her call last?
Mathematics
1 answer:
Luda [366]3 years ago
6 0

Answer:

4 minutes and 32 seconds

Step-by-step explanation:

card $20.00-money left over $15.68            $20.00-$15.68  4.32

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Use long division to find the quotient below. (5x5 -5x3 - 10x2 - 80x) = (x+2)
kykrilka [37]

Answer: c

Step-by-step explanation:

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3 years ago
5 time 5 to the power of 2 simplified
Maksim231197 [3]
Im not sure wym but i think the answer is 20
3 0
3 years ago
Read 2 more answers
All about simulitious equations​
Korolek [52]

Answer:

On occasions you will come across two or more unknown quantities, and two or more equations

relating them. These are called simultaneous equations and when asked to solve them you

must find values of the unknowns which satisfy all the given equations at the same time.

Step-by-step explanation:

1. The solution of a pair of simultaneous equations

The solution of the pair of simultaneous equations

3x + 2y = 36, and 5x + 4y = 64

is x = 8 and y = 6. This is easily verified by substituting these values into the left-hand sides

to obtain the values on the right. So x = 8, y = 6 satisfy the simultaneous equations.

2. Solving a pair of simultaneous equations

There are many ways of solving simultaneous equations. Perhaps the simplest way is elimination. This is a process which involves removing or eliminating one of the unknowns to leave a

single equation which involves the other unknown. The method is best illustrated by example.

Example

Solve the simultaneous equations 3x + 2y = 36 (1)

5x + 4y = 64 (2) .

Solution

Notice that if we multiply both sides of the first equation by 2 we obtain an equivalent equation

6x + 4y = 72 (3)

Now, if equation (2) is subtracted from equation (3) the terms involving y will be eliminated:

6x + 4y = 72 − (3)

5x + 4y = 64 (2)

x + 0y = 8

5 0
3 years ago
A builder of houses needs to order some supplies that have a waiting time Y for delivery, with a continuous uniform distribution
xenn [34]

Answer:

The Expected cosy of the builder is $433.3

Step-by-step explanation:

$400 is the fixed cost due to delay.

Given Y ~ U(1,4).

Calculating the Variable Cost, V

V = $0 if Y≤ 2

V = 50(Y-2) if Y > 2

This can be summarised to

V = 50 max(0,Y)

Cost = 400 + 50 max(0, Y-2)

Expected Value is then calculated by;

Waiting day =2

Additional day = at least 1

Total = 3

E(max,{0, Y - 2}) = integral of Max {0, y - 2} * ⅓ Lower bound = 1; Upper bound = 4, (4,1)

Reducing the integration to lowest term

E(max,{0, Y - 2}) = integral of (y - 2) * ⅓ dy Lower bound = 2; Upper bound = 4 (4,2)

E(max,{0, Y - 2}) = integral of (y) * ⅓ dy Lower bound = 0; Upper bound = 2 (2,0)

Integrating, we have

y²/6 (2,0)

= (2²-0²)/6

= 4/6 = ⅔

Cost = 400 + 50 max(0, Y-2)

Cost = 400 + 50 * ⅔

Cost = 400 + 33.3

Cost = 433.3

5 0
3 years ago
Read 2 more answers
A manager is comparing wait times for customers in a coffee shop based on which employee is
anyanavicka [17]

Using the t-distribution, as we have the standard deviation for the sample, it is found that there is a significant difference between the wait times for the two populations.

<h3>What are the hypothesis tested?</h3>

At the null hypothesis, we test if there is no difference, that is:

H_0: \mu_A - \mu_B = 0

At the alternative hypothesis, it is tested if there is difference, that is:

H_1: \mu_A - \mu_B = 0

<h3>What are the mean and the standard error of the distribution of differences?</h3>

For each sample, we have that:

\mu_A = 73, s_A = \frac{2}{\sqrt{100}} = 0.2

\mu_B = 74, s_B = \frac{4}{\sqrt{100}} = 0.4

For the distribution of differences, we have that:

\overline{x} = \mu_A - \mu_B = 73 - 74 = -1

s = \sqrt{s_A^2 + s_B^2} = \sqrt{0.2^2 + 0.4^2} = 0.447

<h3>What is the test statistic?</h3>

It is given by:

t = \frac{\overline{x} - \mu}{s}

In which \mu = 0 is the value tested at the null hypothesis.

Hence:

t = \frac{\overline{x} - \mu}{s}

t = \frac{-1 - 0}{0.447}

t = -2.24

<h3>What is the p-value and the decision?</h3>

Considering a one-tailed test, as stated in the exercise, with 100 - 1 = 99 df, using a t-distribution calculator, the p-value is of 0.014.

Since the p-value is less than the significance level of 0.05, it is found that there is a significant difference between the wait times for the two populations.

More can be learned about the t-distribution at brainly.com/question/16313918

8 0
2 years ago
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