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2 years ago

Mr. Goldstein is 4 times as old as his daughter Anna. In 4 years, he will be 3 times as old as Anna. How old is Anna now?

Mathematics

1 answer:

trasher [3.6K]2 years ago

6 0

Lets Anna's age = A

Mr. Goldstein age = G

Mr. Goldstein is 4 times as old as his daughter Anna.

So G= 4A

In 4 years, he will be 3 times as old as Anna

we add 4 with Both their ages

G + 4 = three times of A + 4

G + 4= 3(A + 4)

We know G= 4A, replace it in above equation

4A + 4= 3(A + 4)

4A + 4= 3A + 12

Subtract 3A from both sides

A + 4 = 12

Subtract 4 from both sides

A = 8

So Anna's age = 8 years

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The volume of the shape

We have a cylinder that is cut into two. Its external radius is 5ft, while its internal radius is 4ft.

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$\begin{gathered} \text{External radius = 4ft + 1ft } \\ =\text{ 5ft} \end{gathered}$

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Recall that the volume(V) of a full cylinder is:

$V\text{ = }\pi r^2h$

Since the cylinder is cut into two, the volume(V) is:

$V\text{ = }\frac{\pi r^2h}{2}$

height (h) = 12ft (given)

The volume of the shape:

$\begin{gathered} =\text{ Volume of cylinder with a radius of 5ft - Volume of cylinder with a radius of 4ft} \\ =\text{ }\frac{\pi\text{ }\times5^2\text{ }\times\text{ 12}}{2}\text{ - }\frac{\pi\text{ }\times4^2\text{ }\times\text{ 12}}{2} \\ =\text{ 471.239 - }301.593 \\ =169.65ft^3 \end{gathered}$

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4 months ago

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X(.07 )+x = 14.70
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2 years ago

Read 2 more answers

Estimate a 25% tip on a bill of $68.28 by first rounding the bill amount to the nearest ten dollars.

diamong [38]

Answer:

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Step-by-step explanation:

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How can I factorise expressions

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1 year ago

A quality report for a production line shows a score of 59 points on a 65- point inspection test. A passing score is 95% complia

Sholpan [36]

Answer:

The line production did not pass inspection

Step-by-step explanation:

* Lets explain how to solve the problem

- To calculate the percentage of one number with respect to another

divide the number by the another number and multiply the answer

by 100 to convert the answer to percentage

- Ex: 15 people out of a total of 25 were female

the percentage of the female is $\frac{15}{25}*100%=60%$

* Lets solve the problem

- A quality report for a production line shows a score of 59 points on

a 65- point inspection test

- A passing score is 95% compliance

- We need to know did the production line pass inspection

∵ The score of the line production is 59 out of 65

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∴ The percentage of the line production is 90.77%

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∵ 90.77% is less than 95%

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2 years ago