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Recent problems solved by 'edjones'
edjones answered: 7568 problems
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Pipes A and B take 8 hours to fill a pool. Pipe A is twice the size of pipe B. How long would it take to fill the pool using only pipe A?
We believe 2 + 2b = 8 would be a logical starting place, but don't know where to go from there.
Thanks for any help.
1 solutions
Answer 310403 by edjones(7569)   on 2011-05-18 20:32:20 (Show Source):
You can put this solution on YOUR website!a takes a hrs to fill the pool. b takes 2a hrs.
a fills 1/a of the pool in 1 hr. b fills 1/2a of the pool in 1 hr.
1/a + 1/2a = 1/8
8+4=a multiply each side by 8a
a=12 hrs
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Ed
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Length-and-distance/451426: If the Volume of a rectangular solid is 160cm^3 what is the length of one side given the width = 5 and the height = 8.
i tried doing 8^2+5^2 = 89. then i did the 
1 solutions
Answer 310389 by edjones(7569) on 2011-05-18 20:04:40 (Show Source):
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Probability-and-statistics/451045: The number of dry cleaning orders picked up at Sunny Fresh Dry Cleaners was sampled over 12 hour periods. Below is the sample:
142 171 125 91 140 125 97 125 162 142
125 117 89 125 140 128
From this data set, compute the sample mean, median, mode and midrange. Compute the 1st
quartile and 3rd and interpret their meanings.
this is what I have so far and I am stuck
142+171+125+91+140+125+97+125+162+142+125+117+89+125+140+128/16
19361/16
120.6875
91,97,125,125,125,125,125,128,140,140,142,142,162,171,206
middle term/median 128
mode
125 occurs 5 times
97,125,125,125,125,125,128,140,140,142,142,162,171,206
206-91=115
125+125= 250 1st Q 250/3= 83.33
171+206=377 3rd Q 377/2 =
1 solutions
Answer 310181 by edjones(7569) on 2011-05-18 01:08:06 (Show Source):
You can put this solution on YOUR website!From a spreadsheet:
Sum 2,044
Mean 127.75
Median 125
Mode 125
Midrange (171+89)/2 = 130
.
Q1 (16+1)/4=4.25~4. the 4th number is in descending order is 117=Q1
Q3 3(17)/4=12.75~13 the 13th number is 142=Q3
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Ed
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Learn how to use a spread sheet and you will avoid mistakes in addition etc and save a lot of time.
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Numbers_Word_Problems/451035: a long-distance runner left his house running at an average rate of 8 miles per hour. fifteen minutes (one-fourth of an hour) later, his son left his house on his bike traveling on the same route at an average rate of 12 miles per hour. how long will it take the son to catch up with his father?
1 solutions
Answer 310160 by edjones(7569) on 2011-05-18 00:17:03 (Show Source):
You can put this solution on YOUR website!speed * time = distance
Let t=son's time
8(t+.25)=father's dist.
12t=son's dist.
12t=8t+2 distances are equal when the son catches up.
4t=2
t= 1/2 hour.
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Ed
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Parallelograms/451004: Please tell me where we went wrong. The answer does not check out when you put it back into the equation. I know what the right answer is from trial and error, but I can't get the equation to get the right answer for me. WHAT AM I DOING WRONG? HELP!
The problem is: what is the height of a triangle if the base= 1/2h and the area = 196 mmsquared?
height = h
base = 1/2 h
A= 196 mm squared
so
A=1/2bh
A=1/2(1/2h)(h)
196=1/2(1/2h)(h) can't we multiply both sides by 2 to get...?
392=(cancels)(cancels h)(2h) or
392=2h*h
392=2h squared (divide both sides by 2)
196=h squared (take the square root of h and 196)
14=h
So height = 14 and base= 1/2h=1/2(14)/7.
Check answer:
196 = 1/2 (7) (14)
196 = 1/2 * 98
196 does not = 49
1 solutions
Answer 310154 by edjones(7569) on 2011-05-18 00:06:06 (Show Source):
You can put this solution on YOUR website!b=.5h, A=196 mm^2
.5bh=A
.5*.5h*h=196
.25h^2=196
h^2=784
h=28 mm
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Ed
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PS:
196=1/2(1/2h)(h) can't we multiply both sides by 2 to get...?
NO we can't! You can cancel off one 1/2 only when multiplying or dividing. Also (1/2h) is incorrect. (h/2) is correct and easiest. Also h(1/2) is correct.
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I'm glad to help someone who shows their work like you have.
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Numbers_Word_Problems/450992: a pair of fair dice is rolled. Let E denote the event that the number landing uppermost on the first die is a 3, and let F denote the event that the sum of numbers landing uppermost is 6.Determine if e and f are independant events
1 solutions
Answer 310143 by edjones(7569) on 2011-05-17 23:15:07 (Show Source):
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Numeric_Fractions/450672: three-fourths of all student at long beach city college receiver finacial aid. if ther are 1200 students,total,how many receive financial aid
1 solutions
Answer 309988 by edjones(7569) on 2011-05-17 14:11:43 (Show Source):
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Mixture_Word_Problems/450657: One thousand liters a solution was available, but the solution was 60% alchohol. Barry needed a solution which was 50% alcohol. How many liters of alcohol had to be extracted so that the solution would be 50% alcohol?
1 solutions
Answer 309987 by edjones(7569) on 2011-05-17 14:10:36 (Show Source):
You can put this solution on YOUR website!.6*1000=600 L of 100% alcohol are in the solution and 400 L of water.
200 L of alcohol must be removed to make a 50% solution (400L water and 400L alcohol.
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Ed
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Rational-functions/450627: I need help with this 1 question.
For events A and B, P(A) = 4/3 and P(B) = 1/4. Also, P(A and B) = 1/5. Are A and B independent? Explain.
1 solutions
Answer 309973 by edjones(7569) on 2011-05-17 13:34:45 (Show Source):
You can put this solution on YOUR website!P(A|B)=P(A and B)/P(B)= 1/5 / 1/4 = 4/5
P(A|B)<> P(A) so it is not independent.
If it were independent the probability of event A would be the same regardless of whether event B has occurred.
4/5<>4/3
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Ed
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Probability-and-statistics/450570: For Adam the probability a bull's eye with a bow and arrow is .4.
Adam will take 5 shots.
a) What type of probability distribution is this?
b) Complete the chart to show the probability distribution for the random variable X which represents the number of possible bull's eyes its associated probability.
X = # Bull's Eyes P(X)
c) What is the probability that Adam will get at least 2 bull's eyes?
d) How many bull's eyes do you expect him to make?
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A box contains 5 dozen heads of lettuce. There are eight spoiled heads in the box. A person chooses a dozen heads at random.
a) What is the expected number of spoiled heads that will be chosen?
b) What is the probability that he did not choose any of the spoiled heads?
1 solutions
Answer 309956 by edjones(7569) on 2011-05-17 12:37:44 (Show Source):
You can put this solution on YOUR website!A box contains 5 dozen heads of lettuce. There are eight spoiled heads in the box. A person chooses a dozen heads at random.
a) What is the expected number of spoiled heads that will be chosen?
b) What is the probability that he did not choose any of the spoiled heads?
.
a) 8/60 * 12 = 8/5 the expected number of spoiled heads that will be chosen.
.
b)
52C12/60C12 = .1475
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Ed
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Permutations/450494: From a deck of 52 cards, 5 cards are dealt.
What are the odds against each event
a. all from one suit
b. the first 3 from one suit and the last 2 from another
1 solutions
Answer 309855 by edjones(7569) on 2011-05-17 05:30:44 (Show Source):
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Equations/450522: Translate the following problems into algebraic equations. It is not required that you solve the equations; simply translate them. Identify the variables, constants, and coefficients in each equation. Make equations with only one variable and simplify the equation on both sides until there are no parentheses and like terms have been combined.
1)Simplify the algebraic expression
6z + 1 + 4x2 - 3y3 + 7x - 8y2 + 2x2 - x + 5z - 17
and evaluate it for x = -2, y = -3, z = -5.
Identify the variables, constants, and coefficients in the simplified expression.
Translate the following problems into algebraic equations. It is not required that you solve the equations; simply translate them. Identify the variables, constants, and coefficients in each equation. Make equations with only one variable and simplify the equation on both sides until there are no parentheses and like terms have been combined.
2)42 is 40% of what number?
3)15 is what percent of 3?
4)The sum of the page numbers on facing pages of a book is 157; what are the page numbers?
5)A girl buys three apples and seven oranges for $4.56. If an orange costs $0.28 more than an apple, how much does each fruit cost?
1 solutions
Answer 309854 by edjones(7569) on 2011-05-17 05:15:23 (Show Source):
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logarithm/450523: Solve the logarithmic equation. Be sure to reject any value of x that produces the logarithmic of a negative number or the logarithm of 0.
[The 3 next to the second log is suppose to be a base.]
Type an integer or a fraction. Simplify your answer. Use a comma to seperate answers if necessary.
1 solutions
Answer 309853 by edjones(7569) on 2011-05-17 05:13:13 (Show Source):
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real-numbers/450485: a cooler at a picnic contains 100 cans of soda covered by ice. There are 30 cans of cola, 40 cans of orange soda, 10 cans of ginger ale, and 20 cans of root beer. The cans are all the same size and shape. If one can is selected at random from the cooler, determine the probability that the soda selected is ginger ale.
1 solutions
Answer 309831 by edjones(7569) on 2011-05-16 23:13:58 (Show Source):
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Inequalities/450473: I am not sure if I am in the right area but the question they are asking me to answer is for me to determine is -4 a solution. They have x>-4 they want a yes or no answer. I thought no. if some one could please help me!
1 solutions
Answer 309828 by edjones(7569) on 2011-05-16 23:08:10 (Show Source):
You can put this solution on YOUR website!Since x is greater than -4 then -4 can't be a solution.
(-4, infinity) is the solution set. This means that any number greater than -4 is in the solution.
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Ed
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test/450450: I have the problem x(x) + 17x + 67 = -5 and need to solve this using the method Complete The Square, but i cant seem to figure out the steps. I know the answers are -8 and -7 but i need the work on these. Can you please show how to solve this equation using Complete The Square?
1 solutions
Answer 309827 by edjones(7569) on 2011-05-16 22:55:50 (Show Source):
You can put this solution on YOUR website!x^2+17x+67=-5
x^2+17x = -72
x^2 + 17x + 289/4 = -72 + 289/4 Complete the square by dividing 17 by 2 and squaring the result for the 3rd number.
(2x+17)^2/4=1/4
(2x+17)/2=+-1/2 Square root of each side.
2x+17=+-1
2x=-17+-1
x=(-17+-1)/2
x=-9, x=-8
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Ed
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Graphs/450462: I have a question they want me to use the multiplication pronciple to solve this equation -6x<-18 I was thinking that you would divide both sides by -6 and the answer would be 3 not sure if it would be negative or positive or maybe I am going about it all wrong.
1 solutions
Answer 309825 by edjones(7569) on 2011-05-16 22:39:43 (Show Source):
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