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Les calcules avec les heures |
2011-09-09 |
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From johanna:
bonjour
je voudrais pouvoir expliquer a mon fils ces calcules avec les heures, mais franchement je n'y comprend rien, pouvez vous m'aider.
voilà le premier calcul:
1h35min29s - 46min37s
deuxiéme exercice:
calculer la durée d'une emission télévisé qui débute à 20h40min et se termine à 22h17min.
troisiéme exercie:
je suis partie en vacances le 25 juillet. Mes vacances ont durées 2 semaines. Quel jours suis-je revenu?
quatroéme exercice:
je pars de st-pierre, je prend le bus.
je veut arrivé à st-denis à 10h et demi.
je sais que la durée du trajet st-pierre /st-denis est de 1h50min.
a quel heure dois-je partir de st-pierre.
Answered by Claude Tardif. |
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Decartes' circle theorem |
2011-09-07 |
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From Joseph:
Given 3 circles of diameters 50, 55, and 60 units,
Place them externally tangent.
What is the diameter of the outer circumscribing circle,
tangent to all 3 circles? I can attach a pdf if this description is not clear.
Not urgent, this has nothing to do with current assignments,
just wondering if I have developed the best methods?
Answered by Chris Fisher. |
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Composition of functions |
2011-09-05 |
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From Jenna:
Let f(x)=x^2-1 and g(x)=1-2x. Find the indicated values.
1. f(g(1)) and g(f(1))
Thanks,
Jenna
Answered by Penny Nom. |
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The derivative of f(x) = (x+1)^1/2 |
2011-09-05 |
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From Carla:
Find the derivative using the limit process of
f(x) = (x+1)^1/2
Answered by Harley Weston. |
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A tangent to the earth |
2011-09-03 |
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From Vickram:
I have a math problem regarding tangent and circle. My example is as
follows: if a long flat ruler measuring 1500 miles is placed on top of earth
which has a radius of 3960 miles what part (length) of the tangential ruler
will actually be touching the earth and what two parts will not?
Answered by Chris Fisher. |
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Geometry Related Careers |
2011-09-01 |
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From Richard:
Good morning,
I am hoping to find a list of careers that would relate to geometric constructions and tessellations.
I have searched the internet some and some of the sites I have found are a bit questionable or dated. Are there sites that Math Central would recommend?
I could not find anything when I did a search on the site.
Thanks in advance,
RVD
Answered by Walter Whiteley. |
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4 x 2 |
2011-08-30 |
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From Lucjan:
how to sketch a diagram that shows 4x2 expression?
Answered by Penny Nom. |
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Exponential form? |
2011-08-30 |
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From Emily:
I have a 6th grader that needs to find out what is the exponential form of 461,885,811
Answered by Penny Nom. |
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A pattern for a cone |
2011-08-30 |
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From Izzy:
I need to create a cone as a prop and my math is not good enough to create the pattern.
Here are my instructions :
The diameter is 2'5" and it has to be 4 feet tall. It is a giant cone. I want it to be pointy at the end, not truncated.
Answered by Penny Nom. |
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A coin toss game |
2011-08-29 |
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From Aniish:
A and B alternately toss a coin.The first one to turn up a head wins.If no more than 5
tosses each are allowed for a single game,find the probability that the person who tosses
first will win the game?What are the odd's against A losing if she goes first?
Answered by Penny Nom. |
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A border around a flower garden |
2011-08-28 |
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From jessica:
A Landscaper, who just completed a rectangular flower garden
measuring 6 feet by 10 feet, orders 1 cubic yard of premixed
cement, all of which is to be used to create a border of uniform
width around the garden. if the border is to have a
depth of 3 inches, how wide will the border be?
( 1 cubic yard=27 cubic feet)
Answered by Penny Nom. |
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The dimension of the box in centimetres |
2011-08-27 |
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From Eliza:
Find the dimension of the box in centimetres. Then find its volume in cubic centimeters.
The box is 0.7m (l) 0.4 (h) 0.2 (w)
Answered by Penny Nom. |
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An anti-freeze solution |
2011-08-27 |
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From aniish:
The radiator of a jeep has a capacity of 4 gallons. It is filled with an anti-freeze solution
of water and glycol which analyzes 10% glycol.what volume of the mixture must be drawn off and replaced with glycol to obtain a 25% glycol solution? all percentages are by volume
Answered by Penny Nom. |
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58 choose 4 |
2011-08-26 |
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From Jean:
Using only the numbers 1-59, how many times would the
number 23 appear in combinations of 5 numbers?
... Can a list be provided as well?
Thank you very much,
Jean
Answered by Penny Nom. |
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25 billion dollars |
2011-08-26 |
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From Bill:
If you have $25billion dollars, what would the value of this amount become if you inflated it at 4% per year for 55 years?=C2=A0 My TVM calculator will not go this high.
Answered by Penny Nom. |
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