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	Proof of a Unique Solution		2009-07-24
		From muele: Find matrix A such that A is not invertible, and b such that Ax=b has a unique solution Answered by Robert J. Dawson.
	Finding Supplementary Angles		2009-07-24
		From emir: Answered by Robert J. Dawson.
	Circular Measures		2009-07-24
		From onyeka: find the equation of a circle with point [3,7][5,5] and wich center lies on the line x-4y=1 Answered by Robert J. Dawson.
	A degreaser for a fish tank		2009-07-23
		From charlie: 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? Answered by Penny Nom.
	A father and son problem		2009-07-23
		From yomi: 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? Answered by Penny Nom.
	Golfing with an unpopular golfer		2009-07-23
		From Ian: "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?" Answered by Robert Dawson and Victoria West.
	Units digit		2009-07-23
		From Jyll: How do solve for the units digit? And that, what is the units digit of the first 1000 prime numbers? Answered by Robert Dawson.
	Inequalities		2009-07-22
		From Sindhu: prove that 4^79 < ( (2^100) + (3^100) )< 4^80 ? Answered by Robert Dawson.
	Buying pens and staplers		2009-07-22
		From Ellen: 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. Answered by Penny Nom.
	Selling fish		2009-07-22
		From Hemantee: 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. Answered by Penny Nom.
	A sundial on an elliptical cylinder		2009-07-22
		From Leo: 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! Answered by Robert Dawson.
	Area under curve		2009-07-21
		From Morag: What is the area bounded by the curve y=X^2(2-X) and the x axis between x=0 and x=2? Answered by Janice Cotcher.
	The girl guides bake sale		2009-07-20
		From Barbra: 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. Answered by Penny Nom.
	Markup and margin		2009-07-20
		From Deanna: 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? Answered by Harley Weston.
	Annular sector		2009-07-20
		From Ed: 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. Answered by Robert Dawson.

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