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Proof of a Unique Solution |
2009-07-24 |
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muele pose la question : Find matrix A such that A is not invertible, and
b such that Ax=b has a unique solution Robert J. Dawson lui répond. |
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Finding Supplementary Angles |
2009-07-24 |
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emir pose la question :
Robert J. Dawson lui répond. |
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Circular Measures |
2009-07-24 |
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onyeka pose la question : find the equation of a circle with point [3,7][5,5] and wich center lies on the line x-4y=1 Robert J. Dawson lui répond. |
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A degreaser for a fish tank |
2009-07-23 |
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charlie pose la question : I have a tank that is 10 feet in diameter that I want to put floating degreaser in.The rate for the degreaser is 1/2 gallon per square foot of surface water.How do I figure out how many gallons I need? Penny Nom lui répond. |
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A father and son problem |
2009-07-23 |
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yomi pose la question : five years ago, a father was 3 times as old as is son, now their combines age's amount 110 years. what is the present age of the father? Penny Nom lui répond. |
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Golfing with an unpopular golfer |
2009-07-23 |
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Ian pose la question : "We are a group of 8 golfers, one of whom is unpopular. How can we construct a schedule, of two foursomes, so that each person is scheduled to play with him the same number of times. What does the week by week schedule look like?" Robert Dawson and Victoria West lui répond. |
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Units digit |
2009-07-23 |
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Jyll pose la question : How do solve for the units digit? And that, what is the units digit of the first 1000 prime numbers? Robert Dawson lui répond. |
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Inequalities |
2009-07-22 |
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Sindhu pose la question : prove that
4^79 < ( (2^100) + (3^100) )< 4^80 ? Robert Dawson lui répond. |
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Buying pens and staplers |
2009-07-22 |
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Ellen pose la question : one more math question,
six pens and four staplers cost $7.10. four pens and seven staplers cost $9.50
find the cost of one pen and one stapler. Penny Nom lui répond. |
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Selling fish |
2009-07-22 |
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Hemantee pose la question : A fishmonger bought 150kg of fish. he sold 70%of it at the price of Rs90 per kg and the rest at Rs 75 per kg. he made a profit of 42.5 per cent. how much did he pay for the fish. Penny Nom lui répond. |
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A sundial on an elliptical cylinder |
2009-07-22 |
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Leo pose la question : I want to build a sundial where the shadow falls on an elliptical cylinder. I can
calculate the coordinates of the points on the cylinder that I want to mark.
My problem is that I will have to make the surface as a flat sheet and bend it
into an elliptical shape. However, I cannot work out a scheme to transfer
the coordinates I know into a distance that will work when I bend the shape.
Help! Robert Dawson lui répond. |
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Area under curve |
2009-07-21 |
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Morag pose la question : What is the area bounded by the curve y=X^2(2-X) and the x axis between x=0 and x=2? Janice Cotcher lui répond. |
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The girl guides bake sale |
2009-07-20 |
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Barbra pose la question : here is two questions i need help with,
1.)A toastmasters tea was attended by 550 people. Students paid 75 cents for their
tickets, and the adults paid $1.20. if the recipts totaled $525, how many adults and how many
students attended?
2.) One cookie and six bars cost $2.00 at the girl guides bake sale.
At the same sale, three bars and six cookies cost $2.10. Find the cost of one cookie and the
cost of one bar. Penny Nom lui répond. |
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Markup and margin |
2009-07-20 |
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Deanna pose la question : What is the difference between a margin percent and a point margin? For instance. A co-worker sells product. If the wholesale cost of said product is $.20, she multiplies that by 1.7 to get her selling price of $.34. To me, that is a 70% margin on the product (our company is making 70% on top of the purchased price). She considers it a 30 point margin, but to me it is 70%. Does that make sense? Any help? What is the difference between a point margin and a percentage? Harley Weston lui répond. |
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Annular sector |
2009-07-20 |
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Ed pose la question : What is the name for the section of a flat ring (annulus)? Similar to a section on a radar screen, a quadrilateral but the top and bottom are curved. Robert Dawson lui répond. |
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