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1 year 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]1 year 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 .

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Jenny is eight years older then twice her cousin sues age. The sum of their ages is less then 32. What is the greatest age that

maw [93]

Answer:

The age of Sue could be 7 years

Step-by-step explanation:

Jenny is 8 years older than twice her cousin Sue's age.

The first equation will be :

J = 8 + 2S ---------(1)

The sum of their ages is less than 32.

The second equation will be :

J + S < 32 ----------------(2)

Now rearrange both equations :

8 + 2S + S < 32

3S < 32 - 8

3S < 24

S < 24/3

S < 8

S = 7

The age of Sue could be 7 years.

3 0

1 year ago

The state of Wisconsin would like to understand the fraction of its adult residents that consumed alcohol in the last year, spec

leonid [27]

Answer:

The answer is below

Step-by-step explanation:

What we should do is the following:

First, from the random sample of 852 researchers, it is necessary to obtain the number of adult residents who consumed alcohol in the past year.

After the above, we must calculate the proportion of adult residents who consumed alcohol in the last year by dividing the number of adult residents who consumed alcohol in the last year by 852.

After this, we must compare if the proportion is exactly 70% or different from it.

We have the following hypotheses:

Null Hypothesis: The proportion of adult residents who consumed alcohol in the last year in the state of Wisconsin is exactly 70%

Alternative hypothesis: The proportion of adult residents who consumed alcohol in the last year in the state of Wisconsin is not equal to 70%

4 0

1 year ago

Jane wishes to bake an apple pie for dessert. The baking instructions say that she should bake the pie in an oven at a constant

pychu [463]

Answer:

A=152

K= -Ln(0.5)/14

Step-by-step explanation:

You can obtain two equations with the given information:

T(14 minutes) = 114◦C

T(28 minutes)=152◦C

Therefore, you have to replace t=14, T=114 and t=28, T=152 in the given equation:

$114=190-Ae^{-14k} (I) \\152=190-Ae^{-28k}(II)$

Applying the following property of exponentials numbers in (II):

$e^{a}.e^{b}=e^{a+b}$

Therefore $e^{-28k}$ can be written as $e^{-14k}.e^{-14k}$

$152=190-Ae^{-14k}.e^{14k}$

Replacing (I) in the previous equation:

$152=190-76e^{-14k}$

Solving for k:

Subtracting 190 both sides, dividing by -76:

$0.5=e^{-14k}$

Applying the base e logarithm both sides:

Ln(0.5)= -14k

Dividing by -14:

k= -Ln(0.5)/14

Replacing k in (I) and solving for A:

$Ae^{-14(-Ln(0.5)/14)}=76\\Ae^{Ln(0.5)} =76\\A(0.5)=76$

Dividing by 0.5

A=152

7 0

1 year ago

What is the first step to solve for n in the following equation? 3n - 7 = 30

sergejj [24]

Answer:

Simplifying

3n + 7 = 30

Reorder the terms:

7 + 3n = 30

Solving

7 + 3n = 30

Solving for variable 'n'.

Move all terms containing n to the left, all other terms to the right.

Add '-7' to each side of the equation.

7 + -7 + 3n = 30 + -7

Combine like terms: 7 + -7 = 0

0 + 3n = 30 + -7

3n = 30 + -7

Combine like terms: 30 + -7 = 23

3n = 23

Divide each side by '3'.

n = 7.666666667

Simplifying

n = 7.666666667

Step-by-step explanation:

5 0

1 year ago

Read 2 more answers

B) Find the principal that yields an interest of Rs 2240 at the rate of 10% p.a. in 3

murzikaleks [220]

Answer:

1,500

Step-by-step explanation:

8 0

2 years ago