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2 years ago

There are 12 girls in a class this is 40% of the class how many boys are in the class?

Mathematics

2 answers:

Andrew [12]2 years ago

7 0

12x100=1200
1200/40=30
30-12=18
there are 18 boys in the class

Montano1993 [528]2 years ago

3 0

Answer:

The answer is 18 boys.

Step-by-step

To start off, you have to set up the problem as 40 percent over 100 percent equals 12 over x. Next, you multiply 100 and 12. You should get 1,200. Then, you divide 1,200 by 40. You will get 30. 30 is the amount of the whole class. Finally, you should subtract 30 and 12. You will then have your answer, 18.

Hope this helps! :)

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Can someone please help me with this ASAP‼️ Thank You

AVprozaik [17]

Let x = cost of the dishwasher.

The amounts the children are paying are:

Mark =20% = 1/5, so 1/5x

Sorin = 75

Raymond = 1/4x

Stephanie = 75

Kristin = 1/3x

Add them together:

x = 1/5x + 1/4x + 1/3x + 75 + 75

x - ( 1/5x + 1/4x + 1/3x ) = 150

Rewrite fractions with common denominator:

x - ( 12/60x + 15/60x + 20/60x ) = 150

60/60x - 47/60x = 150

13/60x = 150

x = 150/1 • 60/13

x = 9000/13

x = 692.31

The total cost of the dishwasher is $692.31

Now calculate the amount each child pays:

Mark = 1/5 x = 692.31/ 5 = $138.46

Sorin = $75.00

Raymond = 1/4 x = 692.31 / 4 = $173.08

Stephanie = $75.00

Kristin = 1/3 x = 692.31 / 3 = $230.77

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3 years ago

What is the mean of the following data values?<br> 22, 37, 49, 15, 92

attashe74 [19]

Answer:

Step-by-step explanation:

First, you have to add 22+37+49+15+92 to get 215. To find the mean, you need to divide by how much numbers there are (5). So 215 divided by 5 is 43!

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3 years ago

Read 2 more answers

Which angle(s) is Julian describing?

Crank

I’m sorry I can’t help you, i would need more information

6 0

3 years ago

2/3 times 3 times 2/7

fomenos

Answer:

4/7

Step-by-step explanation:

2/7 x 3= 6/7. 6/7× 2/3=4/7

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2 years ago

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In a string of 12 Christmas tree light bulbs, 3 are defective. The bulbs are selected at random and tested, one at a time, until

Juliette [100K]

Using the hypergeometric distribution, it is found that there is a 0.0273 = 2.73% probability that the third defective bulb is the fifth bulb tested.

In this problem, the bulbs are chosen without replacement, hence the <em>hypergeometric distribution</em> is used to solve this question.

<h3>What is the hypergeometric distribution formula?</h3>

The formula is:

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}C_{N-k,n-x}}{C_{N,n}}$

$C_{n,x} = \frac{n!}{x!(n-x)!}$

The parameters are:

x is the number of successes.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

In this problem:

There are 12 bulbs, hence N = 12.

3 are defective, hence k = 3.

The third defective bulb is the fifth bulb if:

Two of the first 4 bulbs are defective, which is P(X = 2) when n = 4.

The fifth is defective, with probability of 1/8, as of the eight remaining bulbs, one will be defective.

Hence:

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}C_{N-k,n-x}}{C_{N,n}}$

$P(X = 2) = h(2,12,4,3) = \frac{C_{3,2}C_{9,1}}{C_{12,4}} = 0.2182$

0.2182 x 1/8 = 0.0273.

0.0273 = 2.73% probability that the third defective bulb is the fifth bulb tested.

More can be learned about the hypergeometric distribution at brainly.com/question/24826394

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2 years ago