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Percents |
2001-04-04 |
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From Cathy:
This isvery embarassing but since math and specifically percentages was my worst subject in school here goes. If I have a figure such as 425 and that amount represents 10% of the total amount how do I find out what the total amount is?
Answered by Penny Nom. |
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f(x), f(x) + 2, f(x +2) |
2001-04-04 |
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From Monica:
Could you explain to me how one should go about graphing functions such as f(x), f(x+2), and so on. Also, how should you explain things such as constants and relationships among functions?
Answered by Penny Nom. |
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128 percent too high |
2001-04-04 |
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From A student:
when pilgrims counted noses, they got a count that was 128 percent too high. if they counted 9120 noses, what was the correct count?
Answered by Claude tardif. |
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preuve par 9 |
2001-04-04 |
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From Michel:
Pourriez-vous m'expliquer en détail comment fonctionne la preuve par 9 (pour une division et une multiplication). Je sais l'appliquer mais je ne sais pas pourquoi ça marche. Je ne retrouve pas la démonstration. Merci de m'aider. Exemple . 17x2=34 ; preuve par neuf : 1+7=8 ; 8x2= 16 ; 1+6=7 et 3+4=7, on peut donc supposer (sans affirmer) que cette multiplication a un résultat juste car la preuve par 9 est bonne, 7=7. Comment fonctionne cette preuve par 9???
Answered by Claude Tardif. |
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Two integrals |
2001-04-03 |
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From Jim:
I'm having trouble with these integrals. Can you help me out? 1)the integral of:
x5 arctan x dx 2)the integral of:
2x5 + 9x4 + 19x3 + 13x2 - 5x - 25
----------------------------------------------- dx
x4 + 4x3 + 5x2
Answered by Claude Tardif. |
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Approximating 260 divided by 3 |
2001-04-02 |
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From Andrew:
Choose the letter of the best estimate. 260 divided by 3 a. 60
b. 70
c. 90
d. 100
Answered by Paul Betts. |
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(8 + 5)5 = (y + 4)4 |
2001-04-01 |
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From Kelley:
(8 + 5)5 = (y + 4)4
What is the value of y?
Answered by Penny Nom. |
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Sigma |
2001-03-31 |
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From A student:
What does the Sigma symbol mean in mathematics?
Answered by Penny Nom. |
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Volume and surface area of a cylinder and a triangular prism |
2001-03-31 |
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From Kevin:
I was wondering how do you find the volume and surface area of a cylinder and a triangular prism.
Answered by Penny Nom. |
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Why K? |
2001-03-30 |
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From Molly:
I was wondering why K is used as the dilation constant for transformation geometry?
Answered by Chris Fisher. |
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Dots on squared paper |
2001-03-30 |
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From Tom:
Consider some squared paper with lines 1cm. apart and dots where the lines cross. Place squares whose sides are whole numbers of centimetres on the paper in such a way that the sides of the squares always lie along the lines on the paper. For each square, find (a)the number of points inside the squares; (b)the number of points on the square and (c)the area of the square. How are these quantities related?
Answered by Leeanne Boehm and Penny Nom. |
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Borrowing from zero |
2001-03-30 |
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From Nikki:
Here is the problem: 5,033.56
- 866.20 Now I know this equals 4,167.36 which I figured out on the calculator just to make sure. But when I did it by hand, I kept ending up with 5,167.36, which I knew was impossible. What am I doing wrong??
Answered by Leeanne Boehm and Claude Tardif. |
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Stem-and-leaf plot |
2001-03-29 |
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From Kelly:
I'm tutoring my 5th grade nephew, and he needs to correct test questions regarding a stem - and - leaf plot. He left his book at school and I'm not familiar with the term. Can you explain it to me so that I can help him?
Answered by Penny Nom. |
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An emergency response station |
2001-03-29 |
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From Tara:
Three cities lying on a straight line want to jointly build an emergency response station. The distance between each town and the station should be as short as possible, so it cannot be built on the line itself, but somewhere east or west. Also, the larger the population of a city, the greater the need to place the station closer to that city. You are to minimize the overall sum of the products of the populations of each city and the square of the distance between that city and the facility. City A is 6 miles from the road's origin, City B is 19 miles away from the origin, and City C is 47 miles from the origin. The populations are 18,000 for City A, 13,000 for City B, and 11,000 for City C. Where should the station be located?
Answered by Claude Tardif and Penny Nom. |
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Cash advance |
2001-03-28 |
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From A student:
dulani has a new credit card. it says: you can get cash advances wherever you are. whenever you want. also if you pay off your balance in full each month for a small transaction fee, the cash is interest free. (see important information on reverse side. On reverese side it says: cash advance transaction fee: $500 or less 2.5%;
$500.01 to $1000.00-2%;
$1000.01 or more -1.5%;
$2.00 minumum.
Annual percentage rater for cash advances 19.8%. dulani wants to know what a cash advance will really cost. Analyze the cash advance terms given here. how much would he pay for a $20 cash advance? What about a $450 cash advance? What annual interest rate are these charges equivalent to? choose other amounts. determine cost and annual ratees for these as well. make recommendations to dulani.
Answered by Penny Nom. |
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