All categories

2 years ago

Tim and Jim are working on a school project together. If he had to work by himself, it would take

Mathematics

1 answer:

Vladimir [108]2 years ago

4 0

Answer: 6 hours

Step-by-step explanation:

Given, Tim and Jim are working on a school project together.

Tim takes 10 hours to complete the school project.

If Jim worked alone, it would take him 15 hours

Let t be the time they both take if they work together.

Then, $\dfrac{1}{t}=\dfrac{1}{\text{Time taken by Tim}}+\dfrac{1}{\text{Time taken by jim}}$

$\Rightarrow\ \dfrac{1}{t}=\dfrac{1}{10}+\dfrac{1}{15}\\\\\Rightarrow\ \dfrac{1}{t}=\dfrac{3+2}{30}=\dfrac{5}{30}\\\\\Rightarrow\dfrac{1}{t}=\dfrac{1}{6}\\\\\Rightarrow t=6$

So, it will take 6 hours to complete the school project together .

You might be interested in

Mei does 6 problems in 18 minutes. How many can she complete in 12 minutes

Dmitriy789 [7]

Do cross multiplication

6 = x
18 12

Now cross multiply

(6)(12) = (18)(x)

72 = 18x

Divide both sides by 18

72 = 18x
18 18

4 = x

So tMei can complete 4 problems in 12 minutes.

5 0

2 years ago

What is 12 divided by 12 i think its 146

MissTica

Answer:

12 divided by 12 is 1

Step-by-step explanation:

A calculator helped me

3 0

2 years ago

Read 2 more answers

Will mark brainliest! (problem below)

Vlad [161]

Answer:

Joe

Hope this helps!

4 0

3 years ago

Read 2 more answers

Two numbers whose sum is 44 and whose product is a maximum

Mashcka [7]

Answer:

x = y = 22

Step-by-step explanation:

It would help to know your math course. Do you know any calculus? I'll assume not.

Equations

x + y = 44

Max = xy

Solution

y = 44 - x

Max = x (44 - x) Remove the brackets

Max = 44x - x^2 Use the distributive property to take out - 1 on the right.

Max = - (x^2 - 44x ) Complete the square inside the brackets.

Max = - (x^2 - 44x + (44/2)^2 ) + (44 / 2)^2 . You have to understand this step. What you have done is taken 1/2 the x term and squared it. You are trying to complete the square. You must compensate by adding that amount on the end of the equation. You add because of that minus sign outside the brackets. The number inside will be minus when the brackets are removed.

Max = -(x - 22)^2 + 484

The maximum occurs when x = 22. That's because - (x - 22) becomes 0.

If it is not zero it will be minus and that will subtract from 484

x + y = 44

xy = 484

When you solve this, you find that x = y = 22 If you need more detail, let me know.

4 0

2 years ago

A doctor is measuring the average height of male students at a large college. The doctor measures the heights, in inches, of a s

RoseWind [281]

Answer:

There is a 95% confidence that the true mean height of all male student at the large college is between the interval (63.5, 74.4).

Step-by-step explanation:

The (1 - α)% confidence interval for population mean is:

$CI=\bar x\pm z_{\alpha/2}\times\frac{\sigma}{\sqrt{n}}$

The (1 - α)% confidence interval for population parameter implies that there is a (1 - α) probability that the true value of the parameter is included in the interval.

Or, the (1 - α)% confidence interval for the parameter implies that there is (1 - α)% confidence or certainty that the true parameter value is contained in the interval.

The 95% confidence interval for the average height of male students at a large college is, (63.5 inches, 74.4 inches).

The 95% confidence interval for the average height of male students (63.5, 74.4) implies that, there is a 0.95 probability that the true mean height of all male student at the large college is between the interval (63.5, 74.4).

Or, there is a 95% confidence that the true mean height of all male student at the large college is between the interval (63.5, 74.4).

4 0

3 years ago