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2 years ago

15

There are 250 bricks used to build a wall that is 20 feet high how many bricks will be used to build a wall is 40 feet high?

1 answer:

Lady bird [3.3K]2 years ago

6 0

Answer:

500 bricks.

Step-by-step explanation:

There are 250 bricks used to build a wall that is 20 feet high how many bricks will be used to build a wall is 40 feet high?

To solve e the above question, we have:

20 feet high = 250 bricks

40 feet high = x bricks

Cross Multiply

20 feet × x bricks = 40 feet × 250 bricks

x bricks = 40 feet × 250 bricks/20 feet

x bricks = 500 bricks

Therefore, 500 bricks will be used to build a wall is 40 feet high.

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10,101 base 2 + 11,011 base 2 =

REY [17]

Answer:

110,000 base 2

Step-by-step explanation:

column 1 [the first position in the number]:

1+1=0, (carry 1<u>)</u>

column 2:

0+1 +<u>1</u> <em>(carried)</em>=0, (carry 1)

column 3:

1+0+<u>1</u><em> (carried)</em>=0, (carry 1)

column 4:

0+1+1 <em>(carried)</em>=0, (carry 1)

column 5:

1+1+1=1, (carry 1)

then you write the last 1 'cause there is n number to add with:

$10,101_{2}+11,011_{2}=110,000_{2}$

In binary system the highest number to write is 1, if you add 1+1, it jumps to 0, and you have to carry 1 to the next position.

If you are not sure about the sum, you can convert the numbers in base 2, to base 10, so you can know if it is correct:

$10,101_{2}=21_{10}\\11,011_{2}=27_{10}\\110,000_{2}=48_{10}$

So 21+27=48.

<em>In decimal system when you add 9+1, it jumps to 0 and then you have to carry 1 to the next position, because the the highest number you can write is 9.</em>

7 0

2 years ago

Which of the following would best be solved using factoring the difference of squares? 2² + 3x - 10 = 0 O 3r² + 12x = 8 2³ +52²

IgorC [24]

Given: Different equations

To Determine: Which would be best solved using difference of two squares

Solution

The factorization of a difference of two squares is given below

$a^2-b^2=(a-b)(a+b)$

Let us examine each of the given equation

$\begin{gathered} x^2+3x-10=0 \\ x^2-2x+5x-10=0 \\ x(x-2)+5(x-2)=0 \\ (x-2)(x+5)=0 \end{gathered}$ $\begin{gathered} 3x^2+12x=8 \\ 3x^2+12x-8=0 \end{gathered}$ $\begin{gathered} x^3+5x^2-9x-45=0 \\ x^2(x+5)-9(x+5)=0 \\ (x+5)(x^2-9)=0 \\ x^2-9=x^2-3^2=(x+3)(x-3) \\ Therefore \\ (x+5)(x+3)(x-3)=0 \end{gathered}$ $\begin{gathered} x^2-25=0 \\ x^2-5^2=0 \\ (x+5)(x-5)=0 \end{gathered}$

From the above,

$\begin{gathered} x^3+5x^2-9x-45=0 \\ AND \\ x^2-25=0 \end{gathered}$

The two equation above can be solved by difference of two square, but the equation below is the easiest solved using differnce of two square

x² - 25 = 0

3 0

1 year ago

mr sanchez owns a square field. the side lengths are 0.9 kilometers. there are 1980 prairie dog burrows in the field. what is th

nata0808 [166]

Density is the measurement of the amount of mass per unit of volume.
In this case we should calculate the density of prairie dog burrows on a square field. This is a surface charge density.It is defined as the total amount of units q per km^2.
to calculate<span> the </span>density of prairie dog burrows, we should divide the total number of prairie dog burrows in the field <span>by the size of the field. Thus,
</span><span>
</span>prairie dog <span>burrows in square kilometers= number of dog burrows/ size of the field

size of the field=0.9*0.9=900*900=180000m^2
1980/180000</span><span> m^2= 0.011 dog burrows in square meter
11 dogs in square kilometer</span>

5 0

2 years ago

a) A large hotel in Miami has 900 rooms (all rooms are equivalent). During Christmas, the hotel is usually fully booked. However

Olegator [25]

Answer:

14.69% probability that this happens

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use 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.

Central Limit Theorem

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

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

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}}$

1000 people were given assurance of a room.

This means that $n = 1000$

Let us assume that each customer cancels their reservation with a probability of 0.1.

So 0.9 probability that they still keep their booking, which means that $p = 0.9$

Probability more than 900 still keeps their booking:

$n = 1000, p = 0.9$

So

$\mu = 0.9, s = \sqrt{\frac{0.9*0.1}{1000}} = 0.0095$

901/1000 = 0.91

So this is 1 subtracted by the pvalue of Z when X = 0.91.

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

By the Central Limit Theorem

$Z = \frac{0.91 - 0.9}{0.0095}$

$Z = 1.05$

$Z = 1.05$ has a pvalue of 0.8531

1 - 0.8531 = 0.1469

14.69% probability that this happens

3 0

2 years ago

Help me pls thxxxxxxxxxx

n200080 [17]

Answer:

brooklyn

Step-by-step explanation:if ur brooklyn do it ur self plese and ty -niki minaj

4 0

2 years ago