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All five angles of a pentagon ABCDE are equal |
2007-08-04 |
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From Jerry:
All five angles of a pentagon ABCDE are equal. The diagonals AC, AD and BD have the same length. Prove that all five sides of the pentagon are equal in length.
Answered by Penny Nom. |
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Induction - divisibility |
2007-08-04 |
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From Jerry:
How would you prove that for any positive integer n, the value of the expression 3^(2n+2) - 8n -9 is divisible by 64.
Answered by Chris Fisher and Penny Nom. |
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Three runners on a circular track |
2007-08-04 |
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From Arul:
A, B and C run around a circular track starting from the same point simultaneously and in the same direction at speeds of 4 kmph, 6 kmph and 8 kmph respectively. If the length of the track is 400 meters, when will A, B and C meet at the starting point for the first time after they started the race?
4 In the above question, when will they meet for the first time after they started the race?
Answered by Penny Nom. |
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The perimeter of a sign |
2007-08-04 |
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From arul:
Hi
Please help me with the below question.
The outline of a sign for an ice-cream store is made by placing 3/4 th of the circumference of a circle with radius 2 feet on top of an isosceles triangle with height 5 feet, as shown above. What is the perimeter, in feet, of the sign?
(A) 3pi+ 3 sqrt3
(B) 3pi + 6 sqrt3
(C) 3pi + 2 sqrt 33
(D) 4pi + 3 sqrt3
(E) 4pi + 6 sqrt3
Answered by Penny Nom. |
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Dirt in a sloped round hole |
2007-08-03 |
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From Ken:
How much dirt do I need to fill a ground hole 20 ft in dia. with a sloping floor that has a ht. of 5" on one side and 12" on the other side?
Answered by Stephen La Rocque. |
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Scalar triple product and volume of a general tetrahedron |
2007-08-03 |
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From Anurag:
how do you prove that
volume of tetrahedron= 1/12 times scalar triple product of vectors a,b and c?
Answered by Stephen La Rocque. |
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Find the area of a regular pentagon inscribed in a circle |
2007-08-03 |
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From Tracy:
Can you please help me with finding the area of a regular pentagon inscribed in a circle using the Pythagorean theorem. The radius of the circle is 5 cm and each side AB = BC = CD = DE = EA = 6 cm.
Answered by Stephen La Rocque, Leeanne Boehm and Chris Fisher. |
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Factorial fraction |
2007-08-03 |
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From Sekhoane:
Expand completely: (N-2)!/N!(9N-1)!
Answered by Stephen La Rocque. |
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Buying and selling apples |
2007-08-03 |
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From Priya:
Gorang bought 60 Kg of apples at Rs 48 per Kg. He sold 70% of the apples at Rs 60 per Kg and the remaining apples at Rs 35 per Kg.Find Gorang's gain or loss percent on the whole transaction.
Answered by Stephen La Rocque. |
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Radical equations |
2007-08-03 |
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From JC:
I have to solve this radical equation using the power rule; squaring twice.
radical 2x+3- radical x+1= 1.
Answered by Stephen La Rocque. |
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How to calculate percentage change |
2007-08-03 |
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From Galland:
I am working on graphs and I need to find the percentage of increase from one figure to another. How do I do that? For instance staff hours for 2006 were 28011 and for 2007 were 31230. How do I find the percentage of increase?
Answered by Stephen La Rocque. |
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What fraction of the letters of the alphabet is each word? |
2007-08-02 |
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From Clayton:
How do I figure this out, the math question has the answers but I have no idea how to get it.
my Mom can't figure it out either.
What fraction of the letters of the alphabet are each word
Man = 3/26
Glasses = 7/26
Integrity = 1/4
computer = 2/9
Answered by Paul Betts and Harley Weston. |
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A statistics example |
2007-08-02 |
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From Claudia:
A particular employee arrives to work some time between 8:00 am - 8:30 am. Based on past experience the Company has determined that the employee is equally likely to arrive at any time between 8:00 am - 8:30 am.
On average, what time does the employee arrive?
What is the standard deviation of the time at which the employee arrives?
Find the probability that the employee arrives exactly at 8:12 am?
Find the probability that the employee arrives between 8:20 am - 8:25 am?
Answered by Har. |
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The height of a pole |
2007-08-02 |
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From lalaine:
Hi, this is my problem..
From a point 50.2 m to the pole, a student measured the angle of elevation to the top of the pole to be 32°. Find the height of the pole if the student's height from his feet to his eyes is about 4 ft.
Answered by Penny Nom. |
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Prisms and pyramids |
2007-08-02 |
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From taryn:
two similarities between prism and pyramid
Answered by Penny Nom. |
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