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2 years ago

a certain job can be done in 20 hours by 4 people. how many people are needed to do the same job in 10 hours?

1 answer:

7 0

If it takes 4 people to get a job done in 20 hours, then in 10 hours, it will take 2 people to complete the same job.
To find out how many people are needed to do this job in 10 hours, we can see that we got to 10 hours by dividing 20 by two so, to see how many people are needed to complete this same job in ten hours, we would just divide 4 people by 2 which is 2 people.
So, in conclusion, if it takes a certain job to be done in 20 hours by 4 people, then it would take 10 hours for that same job to be completed by 2 people.
Glad I could help!

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A rectangle has an area of 12 square feet and a length of 5 feet. What is its width?

Lera25 [3.4K]

Well, you know that the area of the rectangle is 12 square feet. And you know one of the numbers multiplied to get 12 is 5, so divide 12 by 5. You would get 2.4 as the other number needed.
In this case, 5 feet is the width and 2.4 feet is the length.

8 0

3 years ago

Read 2 more answers

Points A, B, C, and D lie on the circle. Solve for the value of X

aliina [53]

Answer:

A 65

Step-by-step explanation:

The angle formed by two chords is 1/2 the sum of intercepted arcs

x = 1/2 (51+79)

x = 1/2(130)

x =65

4 0

3 years ago

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Use the given information to find the exact value of the trigonometric function

eimsori [14]

$\begin{gathered} \csc \theta=-\frac{6}{5} \\ \tan \theta>0 \\ \cos \frac{\theta}{2}=\text{?} \end{gathered}$

Half Angle Formula

$\cos \frac{\theta}{2}=\pm\sqrt[\square]{\frac{1+\cos\theta}{2}}$ $\tan \theta>0\text{ and csc}\theta\text{ is negative in the third quadrant}$ $\begin{gathered} \csc \theta=-\frac{6}{5}=\frac{r}{y} \\ x^2+y^2=r^2 \\ x=\pm\sqrt[\square]{r^2-y^2} \\ x=\pm\sqrt[\square]{6^2-(-5)^2} \\ x=\pm\sqrt[\square]{36-25} \\ x=\pm\sqrt[\square]{11} \\ \text{x is negative since the angle is on the 3rd quadrant} \end{gathered}$ $\begin{gathered} \cos \theta=\frac{x}{r}=\frac{-\sqrt[\square]{11}}{6} \\ \cos \frac{\theta}{2}=\pm\sqrt[\square]{\frac{1+\cos\theta}{2}} \\ \cos \frac{\theta}{2}is\text{ also negative in the 3rd quadrant} \\ \cos \frac{\theta}{2}=-\sqrt[\square]{\frac{1+\frac{-\sqrt[\square]{11}}{6}}{2}} \\ \cos \frac{\theta}{2}=-\sqrt[\square]{\frac{\frac{6-\sqrt[\square]{11}}{6}}{2}} \\ \cos \frac{\theta}{2}=-\sqrt[\square]{\frac{6-\sqrt[\square]{11}}{12}} \\ \\ \end{gathered}$

Answer:

$\cos \frac{\theta}{2}=-\sqrt[\square]{\frac{6-\sqrt[\square]{11}}{12}}$

Checking:

$\begin{gathered} \frac{\theta}{2}=\cos ^{-1}(-\sqrt[\square]{\frac{6-\sqrt[\square]{11}}{12}}) \\ \frac{\theta}{2}=118.22^{\circ} \\ \theta=236.44^{\circ}\text{ (3rd quadrant)} \end{gathered}$

Also,

$\csc \theta=\frac{1}{\sin\theta}=\frac{1}{\sin (236.44)}=-\frac{6}{5}\text{ QED}$

The answer is none of the choices

7 0

1 year ago

Judy worked 8 hours and Ben worked 10 hours. Their combined pay was $80. When Judy worked 9 hours and Ben worked 5 hours, their

pav-90 [236]

Answer:

Judy = $5/hr

Ben = $4/hr

Step-by-step explanation:

Judy's hours at work - x

Ben's hours at work - y

8x + 10y = 80

9x + 5y = 65

Given these two equations above, we get:

10y = 80 - 8x, which means y = 8 - 0.8x.

Substitute y in the second equation with 8 - 0.8x, so we have:

9x + 5 (8 - 0.8x) = 65

9x + 40 - 4x = 65

5x = 25

x = 5

Come back to the first equation, substitute x:

8*5 + 10y = 80

10y = 80 - 40

y = 4

3 0

2 years ago

Which operation properly transforms matrix I to matrix II?

Y_Kistochka [10]

Answer:

Step-by-step explanation:

Replace R1 with 1 and R3 with 0 you have -2(1)+0 which equals 0 and that matches matrix II. Repeat the process with the other numbers in R1 and R3 and they all come out equal therefor the answer is D.

8 0

2 years ago