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The base for a circular pool 2018-06-10
Adam pose la question :
How many sheet of 4ft by 8ft foam would I need to lay under a pool 15dt in diameter
Penny Nom lui répond.
A tangent to a circle 2018-06-10
Bellle pose la question :
Determine the equation of the circle which has its center at (3,1) and tangent 3x-4y+5=0
Penny Nom lui répond.
The inverse square law 2018-06-05
Amy pose la question :

Question about inverse square law ;

Hi, I'm trying to understand some nuances about this law and
have been reading about it a lot online and trying out some homework
for personal interest (hobby ) - not school related.

I understand that the simple formula is ; 1/d^2

I was wondering about what appears to be an oddity to me, that
I came across when I was working with a test example I found at this
link ;


The problem that caught my interest was this one on that page ;

"1) If a bright flashlight has a light intensity of 15.0 candela at a distance 1.00 m from the lens, what is the intensity of the flashlight 100.0 m from the lens?"

So I have a few different questions about this, but the most important
one is, what does it mean if we replace the "1" in ; 1/d^2 with a different value such as a ratio in the form of a decimal value, so instead we have something like this ;



Does this ratio represent a curve then?

I am thinking that the "1" in the normal formula represents a straight line

Some of the links I was researching ;




Penny Nom lui répond.
Are those two equations the same? 2018-06-05
Francisco pose la question :
Solve for y: 2(x+3)=y x=5
Solve for y: (x+3)2=y x=5
Are those two equations the same?

Penny Nom lui répond.
The difference between two numbers is -3 2018-06-05
Hannah pose la question :
write a pair if integers whose difference is -3 ( given that the greater number is 8 )
Penny Nom lui répond.
The volume of a berm 2018-06-04
Mike pose la question :
Have a berm that is 700’ long, 29’ y’all and needs a 20’ top with 5-1 slope on one side and 3-1 slope in the other
Penny Nom lui répond.
Two odd integers 2018-06-04
Pleroma pose la question :
The product of two alternate odd integers exceeds three times the smaller number by 12. What is the larger number?
Penny Nom lui répond.
$96 is 66 2/3% of what dollar amount? 2018-05-31
mary pose la question :
$96 is 66 2/3% of what dollar amount?
Penny Nom lui répond.
Taking 6 pills 2018-05-29
Dave pose la question :
My motives are simple, I want to get revenge on my brother who, unbeknown to me, repeatedly cheated when we played on-line Scrabble! Can you help? - he has posed this question knowing that I'll struggle to get the solution. Question: He is taking 6 pills a day, if he takes the pills in a different order each day, how long will it be before he takes the pills in the same order on the same date again? I think leap years might come in to it! Will I confess to using you guys? - I'll think about that one.
Penny Nom lui répond.
Monthly Pension 2018-05-28
Kenneth pose la question :


I have a question regarding how the units cancel in the following:

A company uses the following calculation to determine the monthly payment for its employees as they retire:

1.1% * average 5 years highest salary * years of service

If an employee worked 33 years and his average 5 year salary is $30,705.17, what is his monthly payment?

I used the following to determine his monthly payment, but I am not sure how the units cancel especially the years.

1.1% * $30,705.17 * 33 years divided by 12 months/year

I determined his payment as $928.83 per month, but the year units do not cancel unless the 1.1% is per year.

Is the correct calculation 1.1%/year * $30,705.17 * 33 years divided by 12 months/year so that the units cancel properly?

The $\$30,705.17$ is an average for 5 years of working. It is not $30,705.17 per year.

I thank you for your assistance.

Penny Nom lui répond.
What is the diameter of the observable universe? 2018-05-27
peter pose la question :
The diameter of the observable universe is calculated to be 92 billion light years. What would that distance be in miles given a light year is 6 trillion miles?
Penny Nom lui répond.
An equation with rational coefficients 2018-05-26
Anagh pose la question :
If x and y are rational number and
(x+y) + (x - 2y)√2 = 2x -y + (x-y-1) √5

Then find the value of x and y.

Penny Nom lui répond.
Converting inches to centimeters 2018-05-25
Jason pose la question :
Is there a method to approximately convert inches to cm in my head without using a calculator?

Thanks! Jason

Penny Nom lui répond.
Pre tax and post tax percentages 2018-05-22
Tom pose la question :
I work in a clothes shop which can also do mail-orders. My Head Office has sent a report with which we can check the records we keep in store tally with those at HO.

According to that report we have taken £2578.25 in orders, excluding VAT (20%), which would therefore be £3093.91 including VAT (2578.25+20%=3093.91).

According to my records, we have taken £3179.32 including VAT, which would be £2543.45 excluding VAT (3179.32-20%=2543.45).

Why is it that the difference between the VAT inclusive figures (3179.32-3093.91) is +£85.41, but the difference between the VAT exclusive figures (2543.45-2578.26) is -£34.81?

Now, I can see from the report that 1 order has not been recorded by HO, and I know that our average order value is around £30, so the -£34.81 makes sense. But surely both figures should be a minus, regardless of whether they include VAT?

I'm sure there is an obvious answer, but I just cannot see it! Any help would be gratefully received.

Penny Nom lui répond.
The area, radius and slant height of a cone 2018-05-18
joette pose la question :
If you have a cone how to find the slant height when given the area and radius?
Penny Nom lui répond.



Centrale des maths reçoit une aide financière de l’Université de Regina et de The Pacific Institute for the Mathematical Sciences.



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