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3 years ago

2800 to 2100 percent of change

Mathematics

1 answer:

Gennadij [26K]3 years ago

7 0

2800-2100=700
2800/700=4
4% decrease

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Jason has volunteered at the pet shelter 3 more times than keith. Jason has volunteered 12 times. which equation represents this

Darya [45]

X= times keith volunteered
$12 = 3x$

4 0

3 years ago

You have a large jar that initially contains 30 red marbles and 20 blue marbles. We also have a large supply of extra marbles of

Dima020 [189]

Answer:

There is a 57.68% probability that this last marble is red.

There is a 20.78% probability that we actually drew the same marble all four times.

Step-by-step explanation:

Initially, there are 50 marbles, of which:

30 are red

20 are blue

Any time a red marble is drawn:

The marble is placed back, and another three red marbles are added

Any time a blue marble is drawn

The marble is placed back, and another five blue marbles are added.

The first three marbles can have the following combinations:

R - R - R

R - R - B

R - B - R

R - B - B

B - R - R

B - R - B

B - B - R

B - B - B

Now, for each case, we have to find the probability that the last marble is red. So

$P = P_{1} + P_{2} + P_{3} + P_{4} + P_{5} + P_{6} + P_{7} + P_{8}$

$P_{1}$ is the probability that we go R - R - R - R

There are 50 marbles, of which 30 are red. So, the probability of the first marble sorted being red is $\frac{30}{50} = \frac{3}{5}$ .

Now the red marble is returned to the bag, and another 3 red marbles are added.

Now there are 53 marbles, of which 33 are red. So, when the first marble sorted is red, the probability that the second is also red is $\frac{33}{53}$

Again, the red marble is returned to the bag, and another 3 red marbles are added

Now there are 56 marbles, of which 36 are red. So, in this sequence, the probability of the third marble sorted being red is $\frac{36}{56}$

Again, the red marble sorted is returned, and another 3 are added.

Now there are 59 marbles, of which 39 are red. So, in this sequence, the probability of the fourth marble sorted being red is $\frac{39}{59}$ . So

$P_{1} = \frac{3}{5}*\frac{33}{53}*\frac{36}{56}*\frac{39}{59} = \frac{138996}{875560} = 0.1588$

$P_{2}$ is the probability that we go R - R - B - R

$P_{2} = \frac{3}{5}*\frac{33}{53}*\frac{20}{56}*\frac{36}{61} = \frac{71280}{905240} = 0.0788$

$P_{3}$ is the probability that we go R - B - R - R

$P_{3} = \frac{3}{5}*\frac{20}{53}*\frac{33}{58}*\frac{36}{61} = \frac{71280}{937570} = 0.076$

$P_{4}$ is the probability that we go R - B - B - R

$P_{4} = \frac{3}{5}*\frac{20}{53}*\frac{25}{58}*\frac{33}{63} = \frac{49500}{968310} = 0.0511$

$P_{5}$ is the probability that we go B - R - R - R

$P_{5} = \frac{2}{5}*\frac{30}{55}*\frac{33}{58}*\frac{36}{61} = \frac{71280}{972950} = 0.0733$

$P_{6}$ is the probability that we go B - R - B - R

$P_{6} = \frac{2}{5}*\frac{30}{55}*\frac{25}{58}*\frac{33}{63} = \frac{49500}{1004850} = 0.0493$

$P_{7}$ is the probability that we go B - B - R - R

$P_{7} = \frac{2}{5}*\frac{25}{55}*\frac{1}{2}*\frac{33}{63} = \frac{825}{17325} = 0.0476$

$P_{8}$ is the probability that we go B - B - B - R

$P_{8} = \frac{2}{5}*\frac{25}{55}*\frac{1}{2}*\frac{30}{65} = \frac{750}{17875} = 0.0419$

So, the probability that this last marble is red is:

$P = P_{1} + P_{2} + P_{3} + P_{4} + P_{5} + P_{6} + P_{7} + P_{8} = 0.1588 + 0.0788 + 0.076 + 0.0511 + 0.0733 + 0.0493 + 0.0476 + 0.0419 = 0.5768$

There is a 57.68% probability that this last marble is red.

What's the probability that we actually drew the same marble all four times?

$P = P_{1} + P_{2}$

$P_{1}$ is the probability that we go R-R-R-R. It is the same $P_{1}$ from the previous item(the last marble being red). So $P_{1} = 0.1588$

$P_{2}$ is the probability that we go B-B-B-B. It is almost the same as $P_{8}$ in the previous exercise. The lone difference is that for the last marble we want it to be blue. There are 65 marbles, 35 of which are blue.

$P_{2} = \frac{2}{5}*\frac{25}{55}*\frac{1}{2}*\frac{35}{65} = \frac{875}{17875} = 0.0490$

$P = P_{1} + P_{2} = 0.1588 + 0.0490 = 0.2078$

There is a 20.78% probability that we actually drew the same marble all four times

3 0

3 years ago

Mr.Marquez had 123 eggs in his refrigerator in his restaurant.He put 32 more cartoons of eggs in the refrigerator.Each cartoon c

skad [1K]

Answer:

2790

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Zahra compares two wireless data plans. Which equation gives the correct value of n, the number of GB, for which Plans A and B c

Elden [556K]

The equation which gives the correct value of n, the number of GB, for which Plans A and B cost the same is 8n = 20 + 6(n-2)

To determine which equation gives the correct value of n, the number of GB, for which Plans A and B cost the same, we will first solve the equations.

For the first equation

8n = 20 + 6n

Collect like terms

8n - 6n = 20

2n = 20

Then, n = 20 ÷ 2

n = 10 GB

For Plan A

No initial fee and $8 for each GB

Here, 10GB will cost 10 × $8 = $80

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, 10GB will cost $20 + (8 × $6) = $20 + $48 = $68

∴ Plans A and B do not cost the same here.

For the second equation

8n = 20(2n) + 6

First, clear the bracket

8n = 40n + 6

Now, collect like terms

40n - 8n = 6

42n = 6

∴ n = 6 ÷ 42

n = 1/7 GB

For Plan A

No initial fee and $8 for each GB

Here, 1/7GB will cost 1/7 × $8 = $1.14

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, 1/7GB will cost $20 (Since the lowest cost is $20)

∴ Plans A and B do not cost the same here.

For the third equation

8n = 20 + 6(n-2)

First, clear the brackets

8n = 20 + 6n - 12

Now, collect like terms

8n - 6n = 20 - 12

2n = 8

n = 8 ÷ 2

n = 4 GB

For Plan A

No initial fee and $8 for each GB

Here, 4GB will cost 4× $8 = $32

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, 4GB will cost $20 + (2 × $6) = $20 + $12 = $32

Plans A and B do not cost the same here.

∴ Plans A and B do cost the same here

For the fourth equation

8n = 20 + 2n + 6

Collect like terms

8n - 2n = 20 + 6

6n = 26

n = $\frac{26}{6}$

n = $\frac{13}{3}$ GB or $4\frac{1}{3}$ GB

For Plan A

No initial fee and $8 for each GB

Here, $\frac{13}{3}$ GB will cost $\frac{13}{3}$ × $8 = $34.67

For Plan B

$20 for the first 2GB and $6 for each additional GB after the first 2

Here, $4\frac{1}{3}$ GB will cost $20 + ( $2\frac{1}{3}$ × $6) = $20 + $14 = $34

∴ Plans A and B do not cost the same here.

Hence, the equation which gives the correct value of n, the number of GB, for which Plans A and B cost the same is 8n = 20 + 6(n-2)

Learn more here: brainly.com/question/9371507

6 0

2 years ago

What is the value of the expression below? 8 plus 24 divided (2 x 6) - 4

Anastaziya [24]

Answer:

Step-by-step explanation:

So, let's right this out:

8+24

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

(2 x 6)-4

When we simplify, we get:

----

Which is 4.

Hope this helped sorry if incorrect!

~Mschmindy

3 0

3 years ago