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1 year ago

selma is now 3 times older than joyce . four years ago , selma was 4 times as old as joyce was then . find their present ages

Mathematics

1 answer:

adoni [48]1 year ago

8 0

Present age of Selma = s

Present age of Joyce = j

Selma is now 3 times as old as joyce

s=3j........(1)

Four years ago,

s-4=j-4

then

Selma was 4 times as old as joyce

s-4=4(j-4)

s-4=4j-16

s=4j-16+4

s=4j-12.............(2)

Put the value of s in (2) from (1)

3j=4j-12

3j-4j=-12

-j=-12

Multiply by -1 both sides

j=12

Put the value of j in (1)

s=3j

s=3(12)

s=36

Present age of Selma = s = 36 years old

Present age of Joyce = j = 12 years old

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Answer:

option D. 4.7 x 10-4 m

Step-by-step explanation:

The correct question is

• cell P: 5.0 x 10-4 meters

• cell Q: 3.0 x 10-5 meters

we have

The diameter of cell P is $5*10^{-4}\ m$

The diameter of cell Q is $3*10^{-5}\ m$

Rewrite the diameter of cell P as

$5*10^{-4}\ m=5*10^{-4}(\frac{10}{10})=50*10^{-5}\ m$

Find the difference

$50*10^{-5}\ m-3*10^{-5}\ m=47*10^{-5}\ m$

Rewrite the difference as

$47*10^{-5}\ m=47*10^{-5}}(\frac{10}{10})=4.7*10^{-4}\ m$

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2 years ago

The Tennessee Tourism Institute (TTI) plans to sample information center visitors entering the state to learn the fraction of vi

baherus [9]

Answer: 2185

Step-by-step explanation:

Let p be the proportion of visitors are campers.

Given : The Tennessee Tourism Institute (TTI) plans to sample information center visitors entering the state to learn the fraction of visitors who plan to camp in the state.

The prior proportion of visitors are campers : p=0.35

Allowable error : E= 2%= 0.02

We know that the z-value for 95% confidence = $z_c=1.96$

Then by Central Limit Theorem , the required sample size would be :

$n=p(1-p)(\dfrac{z_{c}}{E})^2$

$\Rightarrow\ n=0.35(1-0.35)(\dfrac{1.96}{0.02})^2\\\\ n= 0.35(0.65)(9604)$

Simply , we get

$n=2184.91\approx2185$ [Rounded to the next whole number.]

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1 year ago

Find the sequence.. 1,2,2,4,8

AlladinOne [14]

Let the n-th term be called $a_n$

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Hence the sequence will be $1,2,2,4,8,32,256, 8192, 2097152, 17179869184,\dots$

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1 year ago

A polling agency reported that 66 percent of adults living in the United States were satisfied with their health care plans. The

Tpy6a [65]

Answer:

A) The probability is 0.95 that the percent of adults living in the United States who are satisfied with their health care plans is between 63.6% and 68.4%.

Step-by-step explanation:

A polling agency reported that 66 percent of adults living in the United States were satisfied with their health care plans. The estimate was taken from a random sample of 1,542 adults living in the United States, and the 95 percent confidence interval for the population proportion was calculated as (0.636, 0.684).

This means that we are 95% sure that the true proportion of adults living in the United States who were satisfied with their health care plans is between 0.636 and 0.684.

So the correct answer is:

A) The probability is 0.95 that the percent of adults living in the United States who are satisfied with their health care plans is between 63.6% and 68.4%.

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1 year ago

in triangleABC the side lengths are b=13, ac=21 and bc=x. write a compound inequality the represents the range of possible value

tankabanditka [31]

Answer:

8 < x < 34

Step-by-step explanation:

ab = 13, ac = 21, bc = x

The longest side of a triangle must be less than the sum of the other two sides.

If 21 is the longest side:

21 < 13 + x

8 < x

If x is the longest side:

x < 13 + 21

x < 34

Therefore, 8 < x < 34.

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1 year ago