Ask question

Ask question

All categories

2 years ago

11

Three runners — Andy, Blaise, and Susie — were competing in a 100-meter race. When Andy reached the finish line, Blaise was 10 m

eters behind him. When Blaise reached the finish line, Susie was 10 meters behind her. At the moment that Andy reached the finish line, Susie was how many meters behind him? Keep working and you will earn half credit for correctly solved problem.

2 answers:

nikitadnepr [17]2 years ago

8 0

Answer:

20 meters.

Step-by-step explanation:

Well, Andy had finished the 100 meter race before everyone else. This obviously means that he/she had already ran 100 meters. Blaise was 10 meters behind Andy meaning he was at 90 meters. Then Susie was 10 meters behind Susie, meaning Susie was at 80 meters while Andy was at 100. Finally 100-80=20

or

10+10=20

Elena-2011 [213]2 years ago

8 0

Answer:

20 metres

Step-by-step explanation:

I found this on the website this is the correct answer

You might be interested in

a ball is thrown with a slingshot at a velocity of 110ft/sec at an angle of 20 degrees above the ground from a height of 4.5 ft.

satela [25.4K]

Answer:

$t=2.47\ s$

Step-by-step explanation:

The equation that models the height of the ball in feet as a function of time is

$h(t) = h_0 + s_0t -16t ^ 2$

Where $h_0$ is the initial height, $s_0$ is the initial velocity and t is the time in seconds.

We know that the initial height is:

$h_0 = 4.5\ ft$

The initial speed is:

$s_0 = 110sin(20\°)\\\\s_0 = 37.62\ ft/s$

So the equation is:

$h (t) = 4.5 + 37.62t -16t ^ 2$

The ball hits the ground when when $h(t) = 0$

So

$4.5 + 37.62t -16t ^ 2 = 0$

We use the quadratic formula to solve the equation for t

For a quadratic equation of the form

$at^2 +bt + c$

The quadratic formula is:

$t=\frac{-b\±\sqrt{b^2 -4ac}}{2a}$

In this case

$a= -16\\\\b=37.62\\\\c=4.5$

Therefore

$t=\frac{-37.62\±\sqrt{(37.62)^2 -4(-16)(4.5)}}{2(-16)}$

$t_1=-0.114\ s\\\\t_2=2.47\ s$

We take the positive solution.

Finally the ball takes 2.47 seconds to touch the ground

4 0

2 years ago

Select all of the following true statements if R = real numbers, Z = integers, and W = {0, 1, 2, ...}.

PSYCHO15rus [73]

We can start solving this problem by first identifying what the elements of the sets really are.

R is composed of real numbers. This means that all numbers, whether rational or not, are included in this set.

Z is composed of integers. Integers include all negative and positive numbers as well as zero (it is essentially a set of whole numbers as well as their negated values).

W on the other hand has 0,1,2, and onward as its elements. These numbers are known as whole numbers.

W ⊂ Z: TRUE. As mentioned earlier, Z includes all whole numbers thus W is a subset of it.

R ⊂ W: FALSE. Not all real numbers are whole numbers. Whole numbers must be rational and expressed without fractions. Some real numbers do not meet this criteria.

0 ∈ Z: TRUE. Zero is indeed an integer thus it is an element of Z.

∅ ⊂ R: TRUE. A null set is a subset of R, and in fact every set in general. There are no elements in a null set thus making it automatically a subset of any non-empty set by definition (since NONE of its elements are <u>not</u> an element of R).

{0,1,2,...} ⊆ W: TRUE. The set on the left is exactly what is defined on the problem statement for W. (The bar below the subset symbol just means that the subset is not strict, therefore the set on the left can be <u>equal</u> to the set on the right. Without it, the statement would be false since a strict subset requires that the two sets should not be equal).

-2 ∈ W: FALSE. W is just composed of whole numbers and not of its negated counterparts.

3 0

2 years ago

Read 2 more answers

A website reports that 70% of its users are from outside a certain country, and 60% of its users logon the website every day. Su

JulijaS [17]

Answer:

The value is $P (I | L ) = 0.63$

The probability has increased

Step-by-step explanation:

From the question we are told that

The percentage that are from outside the country is $P(O) = 0.70$

The percentage that logs on everyday is $P(L) = 0.60$

The percentage that logs on everyday that are from the inside the country is $P(L | I) = 0.80$

Generally using Bayes' Rule the probability that a person is from the country given that he logs on the website every day is mathematically represented as

$P (I | L ) = \frac{P(I)* P(L|I)}{ P(O) *P(L|O) + P(I) *P(L|I) }$

Where $P(I)$ is the percentage that are from inside that country which is mathematically represented as

$P(I) = 1 - P(O)$

$P(I) = 1 - 0.70$

$P(I) = 0.30$

And $P(L| O)$ is percentage that logs on everyday that are from the outside the country which is evaluated as

$P(L| O) = 1- P(L| I)$

$P(L| O) = 1- 0.80$

$P(L| O) = 0.20$

$P (I | L ) = \frac{ 0.3* 0.80 }{ 0.7 *0.20 + 0.3 * 0.8 }$

$P (I | L ) = 0.63$

Given that the percentage that are from inside that country is $P(I) = 0.30$

and that the probability that a person is from the country given that he logs on the website every day is $P (I | L ) = 0.63$

We see that the additional information increased the probability

5 0

2 years ago

The number of "destination weddings" has skyrocketed in recent years. For example, many couples are opting to have their wedding

Andru [333]

Answer:

There is no sufficient evidence to support the claim that wedding cost is less than $30000.

Step-by-step explanation:

Values (x) ∑(Xi-X)^2

----------------------------------

29.1 0.1702

28.5 1.0252

28.8 0.5077

29.4 0.0127

29.8 0.0827

29.8 0.0827

30.1 0.3452

30.6 1.1827

----------------------------------------

236.1 3.4088

Mean = 236.1 / 8 = 29.51

$S_{x}=\sqrt{3.4088/(8-1)}=0.6978$

Statement of the null hypothesis:

H0: u ≥ 30 the mean wedding cost is not less than $30,000

H1: u < 30 the mean wedding cost is less than $30,000

Test Statistic:

$t=\frac{X-u}{S/\sqrt{n}}=\frac{29.51-30}{0.6978/\sqrt{8}}= \frac{-0.49}{0.2467}=-1.9861$

Test criteria:

SIgnificance level = 0.05

Degrees of freedom = df = n - 1 = 8 - 1 = 7

Reject null hypothesis (H0) if

$t$

Finding in the t distribution table α=0.05 with df=7, we have

$t_{0.05,7}=2.365$

$t>-t_{0.05,7}$ = -1.9861 > -2.365

Result: Fail to reject null hypothesis

Conclusion: Do no reject the null hypothesis

u ≥ 30 the mean wedding cost is not less than $30,000

There is no sufficient evidence to support the claim that wedding cost is less than $30000.

Hope this helps!

5 0

2 years ago

PQ=2x+1 and QR=5x-44; Find PR

Dima020 [189]

Answer:

x=15

Step-by-step explanation:

subtract 1 from both sides so you are left with 2x=5x-45

then subtract 5x from both sides and you have -3x=-45

then finally divide -3 from -45 to get x=15

4 0

2 years ago