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3 years ago

I need help choosing which two equations tool el to find the individual massses of A and B

Mathematics

1 answer:

sineoko [7]3 years ago

3 0

Answer:

Step-by-step explanation:

The third one :

a is twice the mass of b so a=2b
b and 2a combined equal 45

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there are four semi trailer trucks parked in a line at the rest stop after the first truck each truck in the line weighs 2 tons

alexira [117]

Call the weght of the first truck " $w_{1}$ ". We then know that the truck after that is 2 tons more, and the next and the next. i.e:
$w_{2} = w_{1} + 2$
$w_{3} = (w_{2} + 2) = (w_{1}+4)$
$w_{4} = (w_{3} + 2) = (w_{1}+6)$

We also know that total is 32 tons.
$w_{total} = 32 = (w_{1}) + (w_{2}) + (w_{3}) + (w_{4})$
$32 = (w_{1})+(w_{1}+2)+(w_{1}+4)+(w_{1}+6)$
$32= 4(w_{1})+12$
$20=4(w_{1})$
$w_{1} = 5 tons$

Therefore the trukcs weigh 5,7,9 and 11 tons for a total of 32 tons.

Converting to pounds, the trucks weigh 10,000, 14,0000, 18,0000 and 22,000 pounds.

3 0

3 years ago

g A sample of 3 items is chosen at random from a box containing 20 items, out of which 4 are defective. Let X be the number of d

professor190 [17]

Answer:

The variance and standard deviation of X are 0.48 and 0.693 respectively.

The variance and standard deviation of (20 - X) are 0.48 and 0.693 respectively.

Step-by-step explanation:

The variable X is defined as, X = number of defective items in the sample.

In a sample of 20 items there are 4 defective items.

The probability of selecting a defective item is:

$P (X)=\frac{4}{20}=0.20$

A random sample of n = 3 items are selected at random.

The random variable X follows a Binomial distribution with parameters n = 3 and p = 0.20.

The variance of a Binomial distribution is:

$V(X)=np(1-p)$

Compute the variance of X as follows:

$V(X)=np(1-p)=3\times0.20\times(1-0.20)=0.48$

Compute the standard deviation (σ (X)) as follows:

$\sigma (X)=\sqrt{V(X)}=\sqrt{0.48}=0.693$

Thus, the variance and standard deviation of X are 0.48 and 0.693 respectively.

Now compute the variance of (20 - X) as follows:

$V(20-X)=V(20)+V(X)-2Cov(20,X)=0+0.48-0=0.48$

Compute the standard deviation of (20 - X) as follows:

$\sigma (20-X)=\sqrt{V(20-X)} =\sqrt{0.48}0.693$

Thus, the variance and standard deviation of (20 - X) are 0.48 and 0.693 respectively.

3 0

2 years ago

A bowler knocks at least 6 pins 70% of the time.Out of 200 rolls, how many times can you predict the bowler will knock down at l

ankoles [38]

The bowler will hit 6 pins 140 times because 70% of 200 is 140

6 0

3 years ago

Anyone need help understanding coordinates? If so, answer with a link to your question.

cluponka [151]

http://www.mathopenref.com/coordintro.html

http://www.cpalms.org/Public/PreviewResourceAssessment/Preview/70464

3 0

3 years ago

The sum of three number is -44.85. One of the numbers is 24.6. The other two number are equal to each other. What is the value o

tiny-mole [99]

Let the number be x. The other number is also x.

Given the first number is 24.6 and sum is -44.85
24.6 + x + x = -44.85

Combine like terms:
2x + 24.6 = -44.85

Add 24.6 on both sides:
2x = -44.85 - 24.6

Evaluate Right Hand Side:
2x = -69.45

Divide both sides by 2:
x =- 34.725

Answer: The two numbers are both -34.725.

7 0

3 years ago