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2 years ago

What is the surface area of the cube shown? 6.5cm 6.5cm

Mathematics

1 answer:

elena-14-01-66 [18.8K]2 years ago

8 0

Answer:

SA = 253.5 cm

Step-by-step explanation:

SA = 6a^2

SA = 6(6.5)^2

SA = 6(42.25)

SA = 253.50 cm

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What factors cause acid rain in Canada?

vodomira [7]

Answer: The primary cause of low pH in precipitation over northeastern North America is sulphuric acid (H2SO4) from industrial and urban emissions of sulphur dioxide (SO2). Nitric acid (HNO3) generated from emissions of nitrogen oxides (NOx) is a significant contributing factor in this region.

Step-by-step explanation:

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3 years ago

Working together to palms can drain a certain pool in three hours if it takes the older pump nine hours to drain the pool by its

andreyandreev [35.5K]

Answer:

It would take the newer pump 4.5 hours to drain the pool

Step-by-step explanation:

Let's investigate first what is the fraction of the job done in the unit of time (hour in this case) by each pump if the work individually:

older pump: if it takes it 9 hours to complete the job, it does $\frac{1}{9}$ of the job in one hour.

newer pump: we don't know how long it takes (this is our unknown) so we call it "x hours". Therefore, in the unit of time (in one hour) it would have completed $\frac{1}{x}$ of the total job.

both pumps together: since it takes both 3 hours to complete the job, in one hour they do $\frac{1}{3}$ of the job.

Now, we can write the following equation about fractions of the job done:

<em>The fraction of the job done by the older pump plus the fraction of the job done by the newer pump in one hour should total the fraction of the job done when they work together.</em> That is in mathematical terms:

$\frac{1}{9} +\frac{1}{x} =\frac{1}{3}$

and solving for x:

$\frac{1}{9} +\frac{1}{x} =\frac{1}{3} \\x+9=3x\\2x=9\\x=\frac{9}{2} \,\,hours\\x = 4.5\,\,hours$

4 0

3 years ago

The Big Telescope Company sells circular mirrors. Their largest mirrors have radii of 5 meters and their smallest mirrors have r

pogonyaev

Answer: 1:5

Step-by-step explanation:

Given: The cost of every mirror is proportional to the cube of the mirror's radius.

i.e. $\dfrac{\text{Cost of smallest mirror}}{\text{Cost of largest mirror}}=\dfrac{(\text{radii of smallest mirror}^3)}{\text{(radii of largest mirror)}^3}$

Their largest mirrors have radii of 5 meters and their smallest mirrors have radii of 1 meter.

Then,

$\dfrac{\text{Cost of smallest mirror}}{\text{Cost of largest mirror}}=\dfrac{1^3}{(5)^3}=\dfrac{1}{125}$

The ratio of the total cost of 25 of the company's smallest mirrors to the cost of one of the company's largest mirrors will be:

$\dfrac{\text{Cost of 25 smallest mirror}}{\text{Cost of largest mirror}}=\dfrac{25\times 1}{125}=\dfrac{1}{5}$

Hence, the ratio of the total cost of 25 of the company's smallest mirrors to the cost of one of the company's largest mirrors = 1:5 .

5 0

2 years ago

Is correct the number 13

andrey2020 [161]

Yes, the answer is 8.

3 0

3 years ago

Read 2 more answers

Is this right yes or no

posledela

Answer: yes

Step-by-step explanation: [12(1/2)+5(6)] / 3(3) = 36/9 = 4

5 0

2 years ago