Well if he earns $16 per hour.

We count in 16's until 170.

16,3248,64,80,96,112,128,144,160,176

So, it'll take 10hrs. to earn $160.

Do you mean percent?

I learnt this a long time ago.

You have to add up all the number ( In this case )

$${\mathtt{11}}{\mathtt{\,\small\textbf+\,}}{\mathtt{45}}{\mathtt{\,\small\textbf+\,}}{\mathtt{20}}{\mathtt{\,\small\textbf+\,}}{\mathtt{16}}{\mathtt{\,\small\textbf+\,}}{\mathtt{8}}{\mathtt{\,\small\textbf+\,}}{\mathtt{22}} = {\mathtt{122}}$$

And as there was 6 numbers to add up. You have to divide it by  6 to find the mean average. 

$${\frac{{\mathtt{122}}}{{\mathtt{6}}}} = {\frac{{\mathtt{61}}}{{\mathtt{3}}}} = {\mathtt{20.333\: \!333\: \!333\: \!333\: \!333\: \!3}}$$

What is the volume of a rectangular prism with the length of 9 (inches) width of 5(inches) and height of H. the surface area is 202 square inches

V= 9*5*h = 45h

SA=2(9*5+9*h+5*h) = 2(45+9h+5h) = 2(45+14h) =202

2(45+14h) =202

45+14h=101

14h= 56

h=4

V=45h=45*4=180 cubic inches

Well, first of all to get the plus and minus onto the screen you should type it down first.

So look for it on your laptop/computer.

For me, it's on the top-right corner. And to activate the plus I hold (pause) for my laptop.

In some cases it's Ctrl or alt.

But minus, i just have to click it.

+ and -

Where is the 'figure'

Is it under the bed?   It is not under my bed.       Is it under your bed ???

Nice work Zoe   

Here is another way of looking at   137.5 million

A million is 1000000 = 10^6

so   137.5 million = $${\mathtt{137.5}}{\mathtt{\,\times\,}}{{\mathtt{10}}}^{{\mathtt{6}}}$$     now you turn this into an ordinary number by moving the decimal point 6 places in the direction that will make the number bigger!    (you will have to add some zeros)

$$\\137.500000000\times 10^6\\
=137\;\vec{5}\vec{0}\vec{0}\vec{0}\vec{0}\vec{0}.
=137500000$$

Very nice explanation anon 

you have solved it by going backwards.

Can you also do it by setting up an initial equation and solving the equation ?  

I like your answer but I am just setting you a challenge. 

for this question, we can cut it in three different calculations.

1---1x10=10

2---3x1=3

3---9x1/10=9/10=0.9

add them together=10+3+0.9=13.9

i million=1,000,000

137 million=137,000,000

0.5 million=500,000

137.5 million=137,000,000+50,000=137,500,000

so, 137.5 million takes away 100=137,500,000-1000=137,499,000

A times by A would be A²  

so, if the question gives you A² , then you could work out the square root of A² woudl be A.

WOW Alan,  that looks very impressive!    

Look at this number line

Choose any number on the number line.

all numbers to the left of it are smaller AND all numbers to the right of it are bigger.

NOW   you tell me, are any of the minus numbers bigger than any of the positive numbers ??

Lets try to simplify    $$\sqrt{162}$$

I have to look for a squared number that goes into 162

1^1=1     that doesn't help, every number can be divided by 1

2^2=4     no, doesn't go iinto 163

3^2=9     bingo!  9 goes into 162    18 times

$$\\\sqrt{162}\\=\sqr{9*18}\\=\sqrt9*\sqrt{18}\\=3*\sqrt{18}\\$$

now 9 will go into 18 too.    9*2=18

$$\\3*\sqrt{18}\\=3*\sqrt{9*2}\\=3*\sqrt{9}*\sqrt{2\\}=3*3*\sqrt2\\=9\sqrt2$$

And that is how it is done.  If the number under the square root is not divisable by any squared number then the surd cannot be simplified.   

in an example we want to find the squre root of 9 . we will find what number multiplied together mmade 9. so we find the last factor of 9 .

Hi anon,

Your basic logic is good but you have muddled up all your units.

You have feet inches and yards and you have treated them like they are all the same.

Concrete can be purchased by the cubic yard. How much will it cost to pour a slab 17 feet by 17 feet by 2 inches for a patio if the concrete costs $40.00 per cubic yard?

Since the final price is per cubic yard, I might convert everthing to yards from the beginning.

17 feet = $${\frac{{\mathtt{17}}}{{\mathtt{3}}}}$$      yards

2 inches =  $${\frac{{\mathtt{2}}}{\left({\mathtt{12}}{\mathtt{\,\times\,}}{\mathtt{3}}\right)}}$$     yards

So the cost will be

$${\mathtt{40}}{\mathtt{\,\times\,}}\left({\frac{{\mathtt{17}}}{{\mathtt{3}}}}\right){\mathtt{\,\times\,}}\left({\frac{{\mathtt{17}}}{{\mathtt{3}}}}\right){\mathtt{\,\times\,}}\left({\frac{{\mathtt{2}}}{\left({\mathtt{12}}{\mathtt{\,\times\,}}{\mathtt{3}}\right)}}\right) = {\frac{{\mathtt{5\,780}}}{{\mathtt{81}}}} = {\mathtt{71.358\: \!024\: \!691\: \!358\: \!024\: \!7}}$$

=   $71.36

Hi Alan,

Your alternate question and answer fascintates me every time.   

It is so simple yet so confusing (when seen for the first time)

I still get a minor buzz out of that question.  Mmm, I must have mathematics in my blood :)

An infinite number of √2's added together is infinite, so the square root of that is also infinite.

Is that what you really meant?

Form the standard error: s = 73.12/√82

Assuming a 2-sided confidence interval then the upper limit is at a cumulative probability value of 96.92+(100 - 96.92)/2 = 98.46%

Using the t distribution (because we only know the sample standard deviation, not the true population value) this cumulative probability occurs (with 81 degrees of freedom) when t = 2.198 standard errors.

Hence upper limit = 49.75+2.198*73.12/√82

$${\mathtt{ul}} = {\mathtt{49.75}}{\mathtt{\,\small\textbf+\,}}{\frac{{\mathtt{2.198}}{\mathtt{\,\times\,}}{\mathtt{73.12}}}{{\sqrt{{\mathtt{82}}}}}} \Rightarrow {\mathtt{ul}} = {\mathtt{67.498\: \!307\: \!504\: \!130\: \!928\: \!9}}$$

or at approximately 67.5

.

area = π r²

so r = √(21/π)

Now, circumference

= 2 π r

= 2 π √(21/π)

= 2 √(21 π) centimeters

You can work this out on your calculator to get a real number approximation

tan(angle of depression) = height/horizontal distance

so horizontal distance = height/tan(angle of depression)

$${\frac{{\mathtt{1\,700}}}{\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{tan}}{\left({\mathtt{11}}^\circ\right)}}} = {\mathtt{8\,745.741\: \!827\: \!136\: \!861\: \!007\: \!1}}$$

horizontal distance ≈ 8746 ft 

.

Another name for the x axis is the "y=0" line.

So  set 1.5x - 3 = 0 and solve for x

⇔ x = 3 / 1.5

⇔ x = +2

The final step is to substitute this value back into f(x) to check that

it correctly makes f(x) = 0

The intersection with the x-axis occurs when f(x) = 0, so

(3/2)x - 3 = 0

(3/2)x = 3

(1/2)x = 1

x = 2

.