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Lottery Problem |
2007-11-18 |
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From A lottery problem:
There are 50 numbers in a Lottery Draw and 5 numbers are drawn out. The player chooses 5 numbers can you tell what is the lowest number of entries required to guarantee that 3 of the 5 numbers entered match 3 of the 5 numbers drawn?
Answered by Victoria West. |
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A rectangle in an ellipse |
2007-11-18 |
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From David:
I need to find the max area of a rectangle inscribed in an ellipse with the equation
x^2+4y^2=4.. What I have so far is f(x,y)=4xy
g(x,y)=x^2+4y^2-4=0,
y=sqrtx^2-4/4
f'(x)=2x^2/sqrt-4x^2+2(sqrt-4+x^2).
What I need to know is how to finish the problem and find the actual mas area of the rectangle.
David
Answered by Penny Nom. |
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ln (x) - x = ln (2) |
2007-11-18 |
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From James:
How do you make x the subject of
ln (x) - x = ln (2)
Answered by Stephen La Rocque. |
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Red balls and blue balls |
2007-11-18 |
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From Md:
In a group of 15, 7 have Red Balls, 8 have Blue Balls and 3 have neither.
What fraction of the group has both Red Balls and Blue Balls?
Answered by Stephen La Rocque. |
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Find the radius of a circle given the center and a point on the circle |
2007-11-18 |
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From Raymund:
Find the radius if the center is at (0, -5) and one point on the circle is (2,3)
Answered by Stephen La Rocque. |
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Two lines |
2007-11-18 |
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From Kate:
represent qraphically the equations of these lines and their intersecting points
x-y=2
3x+y=11
Answered by Penny Nom. |
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Red hens and white hens |
2007-11-18 |
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From Rapin:
In 15 days, 4 white hens and 3 red hens lay eggs equal to 3 white hens
and 5 red hens lay eggs in 12 days , how many days that white hens can
lay eggs the same amount as red hens lay eggs in 20 days ?
Answered by Steve La Rocque and Penny Nom. |
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A thanksgiving day problem |
2007-11-17 |
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From svetik:
On Thanksgiving Day, a group of nutty professors dressed up as "turkeys" and participated in a local fundraising event. The event consisted of three types of races: the sprint, the relay, and the hurdles. One more “turkey” takes part in the hurdles only than the sprint only. The same number take part in the sprint and the hurdles as take part in the relay and the hurdles. Eleven of the “turkeys” taking some part in these three races do not do the relay. Five “turkeys” take part in the sprint and the relay and three enter all three races. There are four teams of four “turkeys” in the relay. And, one more “turkey” is running in both the relay and the sprint than in the hurdles only.
“Turkey” Coe turned and said to “Turkey” Kim, “How many ‘turkeys’ were taking some part in any of the three races?” The nuttiest math professor, “Turkey” Young, said “There were ________ ‘turkeys’ taking part in any of the three races.”
Fill in the blank!!!
Answered by Penny Nom. |
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A 15% discount |
2007-11-17 |
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From Deanna:
if I purchase an item for $450.00 but get a discount 15% of my item what would then be my total
Answered by syeve La Rocque and Penny Nom. |
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Expand (a^4 - b^4) |
2007-11-17 |
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From Saif:
how would you expand (a^4 - b^4) ???
Answered by Stephen La Rocque and Victoria West. |
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Sides and vertices |
2007-11-17 |
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From derek:
What is the correct name for a 2D geometric shape that would look like one slice from a round pizza and how may sides and vertices would it have? I believe you would say it has one vertex and two sides with the curved boundary not resulting in vertices or a side. Your help is much appreciated.
Answered by Chris Fisher and Walter Whitelty. |
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The game of 24 |
2007-11-17 |
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From Todd:
Hello. My son is very good at the Math 24 game and when he is stumped,
I am usually able to figure it out. However, we are both stumped with
this one. The numbers are 6, 6, 9 and 5. You can use addition, subtraction,
division and multiplication. Please help us equal 24 with those 4 numbers.
Answered by Claude Tardif. |
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Exponential form |
2007-11-16 |
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From ashley:
write a sentence for exponential form.
Answered by Penny Nom. |
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A matrix equation |
2007-11-16 |
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From stephanie:
Im supposed to solve
( 1 tan =E8/2) ( 1 tan =E8/2)^(-1)
(-tan =E8/2 1 ) (-tan =E8/2 1 )
Matrix AA<(-1)=I
Answered by Penny Nom. |
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lim [x + squareroot(x^2 + 3)] as x->-inf |
2007-11-16 |
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From David:
Find the limit. (Hint: treat the expression as a fraction whose denominator is 1, and rationalize the numerator.)
lim [x + squareroot(x^2 + 3)] as x->-inf
i got to
lim -3/(x - squareroot(x^2 + 3)) as x->-inf
but i'm having trouble understanding why the answer is 0 plz explain thx
Answered by Harley Weston. |
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