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Recent problems solved by 'edjones'
edjones answered: 7568 problems
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44 had a membership to the Birch Aquarium
79 had a membership to the San Diego Zoo
28 had both
Construct a Venn diagram
Answer the following questions:
i. How many had only a zoo membership?
ii. How many had only an aquarium membership?
iii. How many belonged to either one or the other or both?
iv. How many belonged to neither?
please some one help me with this and walk me through it
1 solutions
Answer 288674 by edjones(7569)   on 2011-02-17 10:02:11 (Show Source):
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Percentage-and-ratio-word-problems/410558: A customer orders 25,000 batteries. If experience has shown that 2% of batteries produced will be defective, how many batteries must be produced to ensure production of 25,000 good ones? Round to the nearest whole number.
1 solutions
Answer 288669 by edjones(7569) on 2011-02-17 09:39:46 (Show Source):
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Probability-and-statistics/409908: Not all visitors to a certain company's website are customers. In fact, the website administrator estimates that about 12% of all visitors to the website are looking for other websites. Assuming that this estimate is correct, find the probability that, in a random sample of 4 visitors to the website, exactly 3 actually are looking for the website.
Round your response to at least three decimal places.
1 solutions
Answer 288394 by edjones(7569) on 2011-02-16 01:16:44 (Show Source):
You can put this solution on YOUR website!Let x=.88 and y=.12
nCr=4C3=4 coefficient of the binomial expansion.
4x^3y=.3271 Probability exactly 3 actually are looking for the website.
.
Ed
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Equations/409868: How would you write f(x)=5x^2+15x-9 in vertex form?
1 solutions
Answer 288392 by edjones(7569) on 2011-02-16 00:41:50 (Show Source):
You can put this solution on YOUR website!a(x-h)^2+k Vertex form.
f(x)=5x^2+15x-9
=5(x^2+3x)-9
=5(x^2+3x + 9/4 - 9/4) -9
=5(x^2+3x + 9/4)-5(9/4)-9
=5(x + 3/2)^2 - 81/4 So h=-3/2, k=-81/4, a=5 the vertex is (-3/2, -81/4)
.
Ed
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Rational-functions/409874: I need help starting off my homework, in my class we are working on solving rational equations and inequalities and just finished working with asymptotes.
The problem I've tried to work on is:
x 1
__ = ___
x-1 2
The least common multiple to my knowledge is x-1
I am not for certain where to go from there.
Please Help, Thank you
1 solutions
Answer 288391 by edjones(7569) on 2011-02-16 00:02:39 (Show Source):
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Equations/409884: if i make 60 cents when i sell a book. how many books need to be bought or sold in order to make a $100,000 profit?
1 solutions
Answer 288386 by edjones(7569) on 2011-02-15 23:53:23 (Show Source):
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Systems-of-equations/409703: I am stuck on this algebra problem and was hoping that you may be able to help me work it out.
Question: Two planes departed in opposite directions. After three hours the faster plane had travelled twice as far as the slower plane. Find the distance each plane travelled if the distance between the planes was 2250 km
1 solutions
Answer 288311 by edjones(7569) on 2011-02-15 19:37:03 (Show Source):
You can put this solution on YOUR website!x=speed of slower and 2x=speed of faster
st=d
(x+2x)*3=2250
9x=2250
x=250 km/h
3x=750 km. dist slower traveled.
6x=1500 km. dist faster traveled.
.
Ed
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Linear_Equations_And_Systems_Word_Problems/409681: Please help;
Use the discriminant to determine weather the following equations have solutions that are:
A) two different rational solutions
b) two different irrational solutions
c) exactly one rational solution
D) two different imaginary solutions
25x^2=10x-1
1 solutions
Answer 288300 by edjones(7569) on 2011-02-15 19:17:51 (Show Source):
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Linear_Equations_And_Systems_Word_Problems/409678: I am needing some help with this word problem.
in solving the equation (x+3)(x+1)=48, Eric stated the solution would be x+3=48=>x=45
or
(x+1)=48=>x+47
However, at least one of these solutions fails to work when substituted back into the original equation. Why? Help Eric; solve the problem and explain. Remember to show all work.
1 solutions
Answer 288292 by edjones(7569) on 2011-02-15 19:10:23 (Show Source):
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Pythagorean-theorem/402660: The directions are as follows: If c is the measure of the hypotenus, find each missing measure. Round to the nearest 10th if necessary.
a=?, b=15, c=31 I understand how to use the Pythagorean theorem to work problems where c is missing, but here I am confused. I don't even know where to begin.
1 solutions
Answer 284793 by edjones(7569) on 2011-02-01 00:34:20 (Show Source):
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Triangles/402593: How many (distinct) triangles could be formed that have integer side lenghts and a perimeter of 29? Please show the work to help me with my other problems, please and thank you!
1 solutions
Answer 284792 by edjones(7569) on 2011-02-01 00:23:47 (Show Source):
You can put this solution on YOUR website!14 (7)
7 8
6 9
5 10
4 11
3 12
2 13
1 14
.
13 (6)
8 8
9 7
10 6
11 5
12 4
13 3
.
12 (4)
9 8
10 7
11 6
12 5
.
11 (3)
9 9
10 8
11 7
.
10 (1)
10 9
.
Total 21
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Ed
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Proportions/402070: The volumes of 3 balloons are in the ratio 5:6:7. By what fractions of themselves must the first two be increased so that the ratio of the volumes may be changed to 7:6:5?
1 solutions
Answer 284477 by edjones(7569) on 2011-01-31 01:14:41 (Show Source):
You can put this solution on YOUR website!The volumes of 3 balloons are in the ratio 5:6:7.
Let the vol. of the balloons be 5, 6 and 7L respectively
The vol of the last balloon will be unchanged and will be 5/18 of the total volume after the first 2 are inflated more.
5x/18=7 for the 3rd balloon after the 1st 2 have their volumes increased
x=25.2
.
6*25.2/18=8.4L new vol of the 2nd balloon.
.
7*25.2/18=9.8L new vol of the 1st balloon.
.
Fraction of themselves the 1st two must be increased so that the ratio of the volumes may be changed to 7:6:5
8.4/6 = 7/5
9.8/5 = 49/25
.
Ed
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Proportions/402068: How much water must be added to 9 litres of a solution containing 65% alcohol to obtain a solution containing 45% alcohol?
1 solutions
Answer 284462 by edjones(7569) on 2011-01-31 00:04:00 (Show Source):
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Miscellaneous_Word_Problems/402054: The members of Mrs.Grant's class are standing in a circle; they are evenly spaced and are numbered in order. The student with the number 7 is standing directly across from the student with number 17. how many students are in the class?
1 solutions
Answer 284460 by edjones(7569) on 2011-01-30 23:40:54 (Show Source):
You can put this solution on YOUR website!17-7=10 so there are 9 people between them. There have to be 9 people between them on the other side.
9+9+2=20 students in the class.
.
Ed
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Permutations/402052: Three coins are selected from nine coins: 3 dimes, 5 nickels, and 1 quarter. In how many ways can the selection be made so that the value of the coins chosen is at least 25 cents?
I couldn't figure out how to use a combination
1 solutions
Answer 284454 by edjones(7569) on 2011-01-30 23:10:22 (Show Source):
You can put this solution on YOUR website!nCr=Combination of n things taken r at a time.
1C1*8C2=28 One quarter and any other 2 of the other 8 coins.
3C2*5C1=3*5=15 Two dimes and one nickel.
3C3=1 Three dimes
28+16+1=44
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Ed
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Coordinate-system/401722: The height of a tree in a park was 48 inches on April 1. Six months later, the same tree was 52 inches.
What was the rate of change. in inches per month?
A. 26/3
B. 8
C. 12/13
D. 2/3
1 solutions
Answer 284314 by edjones(7569) on 2011-01-30 11:42:57 (Show Source):
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Graphs/401702: Solve each radical inequality by using algebra. If the inequality has no solution, write no solution.
1 solutions
Answer 284312 by edjones(7569) on 2011-01-30 11:39:01 (Show Source):
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