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3 years ago

PLEASE HELP URGENT!!!!!!

Mathematics

1 answer:

arlik [135]3 years ago

6 0

9514 1404 393

Answer:

12/11 = 1 1/11 hours

Step-by-step explanation:

The total rate is the sum of the individual rates in rooms per hour.

Tom can paint 1/4 room per hour.

Sam and Victor can each paint 1/3 room per hour.

Their total rate is ...

1/4 +1/3 +1/3 = 11/12 . . . rooms per hour

The rate in "hours per room" is the inverse of this.

It takes them 12/11 = 1 1/11 hours to paint one room.

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Each week our school’s team travels to other schools for competitions. Today the five members of the gymnastics team and seven w

Aliun [14]

Answer: The answer is 9.

Step-by-step explanation: Given that five members of gymnastics team and 7 members of weight lifting team are travelling in two vans to the rival school for competition. We are to find the number of ways in which they can ride in two vans such that no van contains more than eight passengers and there is at least one member of each team in each van.

Let 'g' and 'w' denote a member of gymnastics team and weight lifting team respectively.

Then, the possibilities are

For 1 g, we can choose 3w, 4w, 5w, 6w.

For 2g, we can choose 2w, 3w, 4w, 5w, 6w.

For 3g, we can choose 1w, 2w, 3w, 4w, 5w.

For 4g, we can choose, 1w, 2w, 3w, 4w.

Therefore, there are (4 + 5 + 5 + 4) = 18 ways.

Since, here the position of the vans does not matter, so the options are double here. Hence, we must divide it by 2.

Thus, the total number of ways = 9.

4 0

3 years ago

Graph the Quadratic Function given.<br> y = -x^2 - 4x - 3

Dovator [93]

Answer:

Concave down

Y-intercept: (0,-3)

X-intercepts: (-1,0) (-3,0)

Vertex: (-2,1)

6 0

3 years ago

The automatic opening device of a military cargo parachute has been designed to open when the parachute is 200 m above the groun

kirill115 [55]

Step-by-step answer:

Given:

mean, mu = 200 m

standard deviation, sigma = 30 m

sample size, N = 5

Maximum deviation for no damage, D = 100 m

Solution:

Z-score for maximum deviation

= (D-mu)/sigma

= (100-200)/30

= -10/3

From normal distribution tables, the probability of right tail with

Z= - 10/3

is 0.9995709, which represents the probability that the parachute will open at 100m or more.

Thus, by the multiplication rule, the probability that all five parachutes will ALL open at 100m or more is the product of the individual probabilities, i.e.

P(all five safe) = 0.9995709^5 = 0.9978565

So there is an approximately 1-0.9978565 = 0.214% probability that at least one of the five parachutes will open below 100m

6 0

4 years ago

Suppose you observe a data point x = 12 and it is known that this data point came from a normal distribution with mean 5 and sta

mihalych1998 [28]

Answer:

The observation would be considered unusual because it is farther than three standard deviations from the mean.

Step-by-step explanation:

Problems of normally distributed samples are 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 Z has an absolute value higher than 2, the observation is considered unusual.

In this problem, we have that:

$\mu = 5, \sigma = 2, X = 12$

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

$Z = \frac{12 - 5}{2}$

$Z = 3.5$

So the correct answer is:

The observation would be considered unusual because it is farther than three standard deviations from the mean.

3 0

4 years ago

Consider the function f(x) = x2 - 6x +8.

MAVERICK [17]

Answer:

A function that has an axis of symmetry at x = 3 is:

f (x) = x ^ 2 - 6x - 1

Step-by-step explanation:

A parabola has an axis of symmetry at x = 3 if the x-value of the vertex is 3.

f(x) = x^2 + 3x + 1 = x^2 + 3x + 9/4 - 5/4 = (x + 3/2)^2 - 5/4 => vertex = (-3/2, -5/4)

f(x) = x^2 - 3x - 3 = x^2 - 3x + 9/4 - 21/4 = (x - 3/2)^2 - 21/4 => vertex = (3/2, -21/4)

f(x) = x^2 + 6x + 3 = x^2 + 6x + 9 - 6 = (x + 3)^2 - 6 => vertex = (-3, -6)

f(x) = x^2 - 6x - 1 = x^2 - 6x + 9 - 10 = (x - 3)^2 - 10 => vertex = (3, -10)

Therefore, f(x) = x^2 - 6x - 1 has an axis of symmetry at x = 3.

Hope This HELPS!!!

8 0

4 years ago