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What percentage of the seniors polled yes? |
2006-03-20 |
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From Jean:
An equal number of juniors and seniors responded to the question, "Do you like math?" Each respondent said yes or no. If 70% of those who said yes were seniors and 80% of those who said no were juniors, what percentage of the seniors polled yes?
Answered by Penny Nom. |
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A bill with a 15% tip and a 10% discount |
2006-03-20 |
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From Tracy:
A $4500 bill is presented, without tax. 10% discount coupon. Add 15% tip with 3 people spitting for the sever.
Answered by Penny Nom. |
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Linear feet on a paper roll |
2006-03-20 |
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From Vishal:
I WOULD WISH TO KNOW OF A STANDARD FORMULA BY WHICH I CAN CALCULATE THE LINEAR FEET OF A PAPER ROLL AS PER THE FOLLOWING DETAILS:-
THICKNESS: 150 GSM (GRAMS PER SQUARE METER)
REEL WIDTH: 85 CM
REEL DIAMETER: 140 CM
REEL INNER CORE: 10 CM
REEL WEIGHT: 946 KG's
Answered by Stephen La Rocque. |
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GCD |
2006-03-20 |
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From Jana:
How can i prove:
if gcd(a,b)=1 then gcd(a+b,ab)=1
Answered by Penny Nom. |
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Quarts, liters cubic yards and soil |
2006-03-19 |
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From Kathy:
I am trying to find out how many quarts of dirt there are in a yard of dirt. The local flower store sells bags of dirt that are 20 quarts or 22 liters for $1.25 and another store sells a yard of dirt for $25.00. Which is the better deal?
Answered by Penny Nom. |
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The day of the week |
2006-03-19 |
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From Neil:
A friend of mine has an excellent memory for dates and events that occurred on that date, but his party piece is the ability to tell you the day of the week that fell of any given date. This talent is all the more extraordinary because the answer comes back in less than 2 seconds (often under 1 second). By his own admission he is no mathematician.
Now his memory and knowledge are without question, but I challenged him that because of its diversity this party piece could not be based upon memory, but on mathematics. I believe that with the correct mathematical approach and the use of a common algorithm, anyone with a basic mathematical mind can do this in their head.
Answered by Chris Fisher. |
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The shape of an egg |
2006-03-19 |
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From Vinson & Julie:
What is the proper mathematical term for the geometric solid that is represented by an egg?
Answered by Chris Fisher. |
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Gross profit as a percentage |
2006-03-18 |
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From Mark:
How do I calculate the gross profit by percentage on and a product I purchased for $23.80 marked up 45% sold for $34.51 = profit of $10.71 GP by percentage????????
Answered by Penny Nom. |
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The square footage of an area in my backyard |
2006-03-17 |
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From Kim:
I need to find out how to calculate the square footage of an area in my backyard that is in the shape of a "slice of pie". There are two sides that are straight lines that come together at the top to form a point, and then at the bottom is a curved line that joins the two other lines together. I need to figure out how to calculate the square footage that is inside the area.
Answered by Penny Nom. |
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Building a flower bed |
2006-03-17 |
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From Bobby:
I am building a flower bed 60 ft long by 8 ft wide by 3 ft deep. How much dirt will it take to fill it with top soil/dirt.
Answered by Penny Nom. |
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9, 8, 7 and 2 in the game of 24 |
2006-03-17 |
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From Alana:
I just began student teaching in a 5th grade math class and found that the students play 24 in class, a game that I used to play in elementary school. The students choose a card which shows 4 numbers and then have to use any combination of addition, subtraction, multiplication, and division to reach 24. There was one card that we found that seems to have all of us stumped. The four numbers are 9, 8, 7 and 2. Can you figure out how to make 24 with those? Thanks so much for your help!
Answered by Claude Tardif. |
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A proof by contraposition |
2006-03-16 |
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From Eban:
1)by mathematical induction prove that 12 + 32 + 52 + ...... + (2k-1)2 = (1/3)k(2k-1)(2k+1) for all positive integers k.
2)show that the contrapositive of the following statement is true. if 1 + M7 is even, then M is odd.
Answered by Stephen La Rocque. |
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If a circle is elongated into an oval .. |
2006-03-16 |
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From Bruce:
If a circle is elongated into an oval, with constant circumference, does the area remain constant?
Answered by Walter Whiteley. |
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Back to the nines |
2006-03-15 |
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From Victoria:
Can you answer this problem, does an answer exist?
- Get a set of numbers 1-9 !
- Using the whole set of nine number tiles (digits 1-9), try to arrange them to make three 3-digit numbers so that the sum of the first two is the third.
Can this be done without carrying over? If not can it be done without carrying over into the hundreds column?
Answered by Claude Tardif. |
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A 3-dimensional star |
2006-03-15 |
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From Rachel:
I am trying to figure out the name of a figure that consists of 8 (I think) square pyramids. There is a net drawing of this figure somewhere and I can't find it because I don't know the name. When all 8 pyramids are connected, they form a '3-dimensional star'. We did this project when I was 14 years old and I am now a 27 year old teacher and I would love to do this project with my kids.
Answered by chris Fisher. |
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