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Word_Problems_With_Coins/363542: A bag contains 208 coins made up of dollars, quarters, dimes & nickels. The total equals $77.10. How many of each type of coin are in the bag?
So far I have:
a=1.0, b=0.25, c=0.1, d=0.05
a+b+c+d=7
a+.25b+.1c+.05d=77.10
I have the answer through trial & error of 57 dollars, 56 quarters, 27 dimes & 68 nickels but can't figure out the complete system of equations to get me there.
1 solutions
Answer 259252 by Fombitz(13828) on 2010-10-29 11:23:39 (Show Source):
You can put this solution on YOUR website!
Where'd the  come from??
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Let X be the number of dollars, Q quarters, D dimes, and N nickels.
1. 
2. 
From eq. 1,

Substituting,

Since you do not have any other equations, you have a Diophantine equation in three variables.
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The procedure to solve it is not much different than trial and error so I'm not sure I'm adding much.
Here's a link to show you how to solve these type of equations if you're interested.
http://mathforum.org/library/drmath/view/61325.html
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test/363546: The diameter of apples in a certain orchard are normally distributed with a mean of 5.55 inches and a standard deviation of 0.65 inches. Show all work.
(A). What percentage of the apples in this orchard have diameters less than 5.8 inches?
(B). What percentage of the apples in this orchard are larger than 6.3 inches?
Could you explain the steps so I can understand?
1 solutions
Answer 259250 by Fombitz(13828) on 2010-10-29 11:08:45 (Show Source):
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Probability-and-statistics/363489: The diameter of apples in a certain orchard are normally distributed with a mean of 5.5 inches and a standard deviation of 0.65 inches. Show all work.
What percentage of the apple in this orchard have diameters less than 5.8 inches?
What percentage of the apples in this orchard are larger than 6.3 inches?
I can work the first part but I don't undersand how to get the second part. Can anyone show me what to do?
z(5.8) = (5.8 -5.55)/0.65 = 0.385
P(x < 5.8) = P(z < 0.385) = ? 1 solutions
Answer 259249 by Fombitz(13828) on 2010-10-29 11:06:25 (Show Source):
You can put this solution on YOUR website!First, your z value is off (you used 5.55 instead of 5.5).

67.8%
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89.1% of apples have diameter less than or equal to  .
100%-89.1%=10.9% have diameters greater than  .
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Graphs/363524: How do you graph -5x+2y>10?? I believe it has to be shaded also. 1 solutions
Answer 259243 by Fombitz(13828) on 2010-10-29 10:55:02 (Show Source):
You can put this solution on YOUR website!

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Plot the line 
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Now choose a test point in either plane, not on the line.
(  ,  ) is a good choice.
Test the inequality.
If the inequality is satisfied, shade the region containing (  ,  ).
If not, shade the other region.
False, shade the region not containing (  ,  )
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Geometry_Word_Problems/363515: A sample of an alloy is in the shape of a solid sphere with a radius of 6.4cm. If this sphere is melted down and then cast into a cube, what is the length of an edge of the cube? 1 solutions
Answer 259207 by Fombitz(13828) on 2010-10-29 09:17:53 (Show Source):
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Probability-and-statistics/363516: a box contains several slips of paper each slip is written an odd number between 2 and 10. without looking, you draw one slip of paper. what is the sample space for the experiment? 1 solutions
Answer 259206 by Fombitz(13828) on 2010-10-29 09:13:46 (Show Source):
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Angles/363469: Morning Everyone,
Struggling on this particular question, on vectors and scalars, was just wondering if anybody could help.
a) Draw an xy plane and show the vectors a=2i+3j and b=5i+j (need not be to scale). By constructing the appropriate parrallelogram, draw the resultant vector in terms of i and j.
b) A particle P is acted upon by forces (measured in Newtons) F1= 3i-2j+5k F2= -i+7j-3k, F3= 5i-j+4k and F4 = -2j+3k. Show the magnitude of the resultant force F acting on P is sqrt134 Newtons.
Many thanks in advance for any help
1 solutions
Answer 259202 by Fombitz(13828) on 2010-10-29 09:09:32 (Show Source):
You can put this solution on YOUR website!a)

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 =(  ,  ) :Blue
 =(  ,  ) :Black
 =(  ,  )=(  ,  ) :Green
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b)
 =(  ,  ,  )
 =(  ,  ,  )
 =(  ,  ,  )
 =(  ,  ,  )
 =  =(  ,  ,  )=(  ,  ,  )
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Trigonometry-basics/363270: If f on my graph is (-5, -2) (-3, -1) (2,1) (-1, 1) (0,0) (1, -1)
and g is (-3, -3) (-1, -3) (0,0) (2, -2) (3, 0) (4, -1)
what is (f-g)(-1) 1 solutions
Answer 259136 by Fombitz(13828) on 2010-10-28 23:27:30 (Show Source):
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test/363294: Please help me solve this equation:
Explain why the following integrals are improper and determine whether they are
convergent or divergent. Evaluate those that are convergent.
a. 
b. 
c. 
d.  1 solutions
Answer 259132 by Fombitz(13828) on 2010-10-28 23:22:38 (Show Source):
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