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3 years ago

a car travels 30 1/5 miles in 2/5 of an a hour. what if the average speed, in miles, per hour of the car?

Mathematics

2 answers:

Mekhanik [1.2K]3 years ago

8 0

Answer:

Average speed of the car is $75.5\text{ miles per hour}$ .

Step-by-step explanation:

We are given the following information:

Distance traveled by the car =

$30\displaystyle\frac{1}{5}\text{ miles}$

Time taken by the car =

$\displaystyle\frac{2}{5}\text{ hours}$

Formula:

Speed = $\displaystyle\frac{\text{Distance covered}}{\text{Time taken}}$

Putting all the values,

$\text{Speed} = \displaystyle\frac{30\frac{1}{5}}{\frac{2}{5}} = \frac{\frac{151}{5}}{\frac{2}{5}} = \frac{151}{2} = 75.5\text{ miles per hour}$

Average speed of the car is $75.5\text{ miles per hour}$ .

alekssr [168]3 years ago

6 0

Answer:

Average speed = 30.2 miles / .4 hours =

75.5 mph

Step-by-step explanation:

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The sum of 3 consecutive integers is 171. what is the first number in this sequence?

NemiM [27]

56 57 and 58 are the three numbers that work

4 0

3 years ago

Because not all airline passengers show up for their reserved seat, an airline sells 125 tickets for a flight that holds only 12

melamori03 [73]

Answer:

98.75% probability that every passenger who shows up can take the flight

Step-by-step explanation:

For each passenger who show up, there are only two possible outcomes. Either they can take the flight, or they do not. The probability of a passenger taking the flight is independent from other passenger. So the binomial probability distribution is used to solve this question.

However, we are working with a large sample. So i am going to aproximate this binomial distribution to the normal.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

The probability that a passenger does not show up is 0.10:

This means that the probability of showing up is 1-0.1 = 0.9. So $p = 0.9$

Because not all airline passengers show up for their reserved seat, an airline sells 125 tickets

This means that $n = 125$

Using the approximation:

$\mu = E(X) = np = 125*0.9 = 112.5$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{125*0.9*0.1} = 3.354$

(a) What is the probability that every passenger who shows up can take the flight

This is $P(X \leq 120)$ , so this is the pvalue of Z when X = 120.

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{120 - 112.5}{3.354}$

$Z = 2.24$

$Z = 2.24$ has a pvalue of 0.9875

98.75% probability that every passenger who shows up can take the flight

7 0

2 years ago

(-6, -4); y = 1/3x +1

Sedbober [7]

Answer:

y=3x+14

Step-by-step explanation:

Well you already know that the slope is 3

parallel lines always have the same slope.

so then you plug in the point (-6,-4) into y=3x+b

-6 is x and -4 is y

-4=3(-6)+b

-4=-18+b

14=b

so your equation is y=3x+14

<em>Hope this helps :D</em>

5 0

2 years ago

Omae wa sinderou nani (questions in the image btw)

Korvikt [17]

Let $a$ be the number of hours worked at Job A and $b$ the number of hours at Job B. Then

$a+b=30$

and

$7.5a+8b=234.50$

From the first equation,

$b=30-a$

and substituting this into the second gives

$7.5a+8(30-a)=234.50\implies-0.5a+240=234.50$

$\implies0.5a=5.50$

$\implies\boxed{a=11}$

5 0

3 years ago

What is (6 + 6 + 6) · (6² + 1²)?<br><br> Please don't tell the answer is the devil number.

VikaD [51]

(6+6+6)(36+1) = (18)(37) = 666. ... If you don't want an answer posted, there's a simple solution ... don't post the question ! And if it still mysterously somehow appears, then for heaven's sake, don't offer points as a reward for an answer. ... Finally ... devil's numbers belong in the Old Wives' Hooey category, not in the Mathematics one. They're not real.

8 0

3 years ago