sarah can complete a project in 90 minutes and her sister betty can complete it in 120 minutes if they both work on the project at the same time how long will it take them to complete the project

Answers

Answer 1

Answer:

Answer:

It will take them approximately 51.43 minutes to complete the project together

Step-by-step explanation:

This is what is called a "shared job" problem.

The best way to work on them is to start by finding the "portion" of the job done by each of the people in the unit of time.

So, for example, Sarah completes the project in 90 minutes, so in the unit of time (that is 1 minute) she completed 1/90 of the total project

Betty completes the project in 120 minutes, so in the unit of time (1 minute) she completes 1/120 of the total project.

We don't know how long it would take for them to complete the project when working together, so we call that time "x" (our unknown).

Now, when they work together completing the entire job in x minutes, in the unit of time they would have done 1/x of the total project.

In the unite of time, the fraction of the job done together (1/x) should equal the fraction of the job done by Sarah (1/90) plus the fraction of the job done by Betty. This in mathematical form becomes:

$(1)/(x) =(1)/(90) +(1)/(120)\n(1)/(x) =(4)/(360) +(3)/(360)\n(1)/(x) =(7)/(360) \nx=(360)/(7) \nx=51.43\,\,min$

So it will take them approximately 51.43 minutes to complete the project together.

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Which fraction is the greatest (represents the largest quantity) ? a.1/3 b.3/8. c.2/5 d.1/2

Answers

Answer:

D. $(1)/(2)$

Step-by-step explanation:

If you have a pie for example and you cut it in half you have two seperate big pieces. On the other hand if you you were to cut it for example 1/3 times that 1 piece out of the three would be smaller than your half.

-Hope this helps :)

Hellllllllllllllllllp plzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

Answers

Answer:

33 units³

Step-by-step explanation:

V= whl

V= 3*3*11/8

v= 33

0.78 of air is nitrogen and 0.93% is argon. Is there more nitrogen or argon in air?

Answers

There is more argon in the air.

An author argued that more basketball players have birthdates in the months immediately following July 31, because that was the age cutoff date for nonschool basketball leagues. Here is a sample of frequency counts of months of birthdates of randomly selected professional basketball players starting with January: 390, 392, 360, 318, 344, 330, 322, 496, 486, 486, 381, 331 . Using a 0.05 significance level, is there sufficient evidence to warrant rejection of the claim that professional basketball players are born in different months with the same frequency? Do the sample values appear to support the author's claim?

Answers

Answer:

There is sufficient evidence to warrant rejection of the claim that professional basketball players are born in different months with the same frequency.

Step-by-step explanation:

In this case we need to test whether there is sufficient evidence to warrant rejection of the claim that professional basketball players are born in different months with the same frequency.

A Chi-square test for goodness of fit will be used in this case.

The hypothesis can be defined as:

H₀: The observed frequencies are same as the expected frequencies.

Hₐ: The observed frequencies are not same as the expected frequencies.

The test statistic is given as follows:

$\chi^(2)=\sum{((O-E)^(2))/(E)}$

The values are computed in the table.

The test statistic value is $\chi^(2)=128.12$ .

The degrees of freedom of the test is:

n - 1 = 12 - 1 = 11

Compute the p-value of the test as follows:

p-value < 0.00001

*Use a Chi-square table.

p-value < 0.00001 < α = 0.05.

So, the null hypothesis will be rejected at any significance level.

Thus, there is sufficient evidence to warrant rejection of the claim that professional basketball players are born in different months with the same frequency.

HELP!!!!! I do not understand how to do this! Could someone please explain to me how I would solve this problem? A computer manufacturer built a new facility for assembling computers. There were construction and new equipment costs. The company paid for these costs and made combined profits of $10 million after 4 years, as shown in the graph:

There is a graph of a line with Years on the x axis and Profits in millions on the y axis that passes through 0, negative 20 and 4, 10.