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3 years ago

Are there about 100 elements

Mathematics

2 answers:

rjkz [21]3 years ago

4 0

Yea but there are precisely 118 total that we know of

Mrac [35]3 years ago

3 0

There are about 100 elements, I believe that there were 115 elements in 2001 , now the periodic table contains 118 elements .

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A box of Georgia peaches has 3 bad and 12 good peaches. (a) If you make a peach cobbler of 12 peaches randomly selected from the

Eddi Din [679]

Answer:

a) 0.21% probability that there are no bad peaches in the peach cobbler.

b) 99.79% probability of having at least 1 bad peach in the peach cobbler

c) 7.91% probability of having exactly 2 bad peaches in the peach cobbler.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

The order in which the peaches are chosen is not important. So the combinations formula is used to solve this question.

Combinations formula:

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

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

(a) If you make a peach cobbler of 12 peaches randomly selected from the box, what is the probability that there are no bad peaches in the peach cobbler?

Desired outcomes:

12 good peaches, from a set of 12. So

$D = C_{12,12} = \frac{12!}{12!(12 - 12)!} = 1$

Total outcomes:

12 peaches, from a set of 15. So

$T = C_{15,12} = \frac{15!}{12!(15 - 12)!} = 455$

Probability:

$p = \frac{D}{T} = \frac{1}{455} = 0.0021$

0.21% probability that there are no bad peaches in the peach cobbler.

(b) What is the probability of having at least 1 bad peach in the peach cobbler?

Either there are no bad peaches, or these is at least 1. The sum of the probabilities of these events is 100%. So

p + 0.21 = 100

p = 99.79

99.79% probability of having at least 1 bad peach in the peach cobbler

(c) What is the probability of having exactly 2 bad peaches in the peach cob- bler?

Desired outcomes:

2 bad peaches, from a set of 3.

One good peach, from a set of 12.

$D = C_{3,2}*C_{12,1} = \frac{3!}{2!(3-2)!}*\frac{12!}{1!(12 - 1)!} = 36$

Total outcomes:

12 peaches, from a set of 15. So

$T = C_{15,12} = \frac{15!}{12!(15 - 12)!} = 455$

Probability:

$p = \frac{D}{T} = \frac{36}{455} = 0.0791$

7.91% probability of having exactly 2 bad peaches in the peach cobbler.

3 0

3 years ago

The value of the solid's surface area is equal to the value of the solid's volume. find the value of x. 5*6*x

velikii [3]

<h3>Given</h3>

a cuboid with length, width, height dimensions 5, 6, x

the value of x that makes the numerical value of the total surface area equal to the numerical value of the volume

<h3>Solution</h3>

The volume is given by

... V = L·W·H = 5·6·x = 30x

The area is given by

... A = 2(L·W + H(L+W)) = 2(5·6 +x(5+6)) = 2(30 +11x) = 60 +22x

When these are equal, we have

... 30x = 60 +22x

... 8x = 60

... x = 7.5

The desired value of x is 7.5.

7 0

3 years ago

2x + y = 7<br> -2x - y = 6<br> Solve systems of equations by substitution

ehidna [41]

Answer:

No solution.

Step-by-step explanation:

2x + y = 7

-2x - y = 6

From the first equation:

y = 7 - 2x

Plug this into the second equation:

-2x - (7 - 2x) = 6

-2x + 2x = 6 + 7

0 = 13

this doesn't make sense so theer is:

No solution.

4 0

2 years ago

Pls help. It’s geometry

Mariulka [41]

The answers are:
H
A
F
A

5 0

3 years ago

Clairemont runs 10 km in 1 hour. how many kilometers does she run in half and hour? in 2 1/2 hours?

Darya [45]

She would run 15 km in an hour and a half and 25 km in 2 1/2 hours

3 0

3 years ago