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Recent problems solved by 'edjones'
edjones answered: 7568 problems
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2. An automobile was driven 84 miles and used 3 gallons of gasoline. At the same rate of consumption, how far would the car travel on 14.5 gallons of gasoline?
3. If a 56-gram serving of pasta contains 7 grams of protein, how many grams of protein are ina 454-gram box of pasta?
4. A garage mechanic purchases oil in a 50 gallon container for changing oil in a customer's cars. After 35 oil changes required 5 qt each, how much oil is left in the 50 gallon container?
5. A dieter has lost 3 lb in 5 weeks. At this rate, how long will it take the dieter to lose 36 lbs? 1 solutions
Answer 247574 by edjones(7569) on 2010-09-21 15:03:30 (Show Source):
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Probability-and-statistics/346105: A typical statistics class with 60 students contains 45 females and 25 seniors. Of the seniors 18 are female. If we randomly choose one student from the class, what is the probability that the selected student is female or a senior? 1 solutions
Answer 247570 by edjones(7569) on 2010-09-21 14:58:12 (Show Source):
You can put this solution on YOUR website!Making a Venn diagram is the easieset way to visualize the following.
45 * 25/60 = 18.75 both seniors and women
45-18.75=26.25 female / non senior
25-18.75=6.25 senior / non female
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(18.75+26.25+6.25)/60
=51.25/60
=.8542 the probability that the selected student is female or a senior.
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Ed
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Permutations/346114: A committee consists of 6 teachers, one each from schools A, B, C, D, E, F. What is the probability that a reporter visiting the committee will be able to correctly guess which teacher belongs to which school (with no hints or identifying information provided)? 1 solutions
Answer 247562 by edjones(7569) on 2010-09-21 14:33:17 (Show Source):
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Probability-and-statistics/346056: Find the probability that in a class of 28 students exactly four were born in each of the seven days of the week. 1 solutions
Answer 247549 by edjones(7569) on 2010-09-21 13:50:56 (Show Source):
You can put this solution on YOUR website!For eaxctly four on Mon. expand the binomial (a+b)^28 where a=1/7 and b=6/7
20475(1/7)^4(6/7)^24=.2109
Tues: 10626(1/6)^4(5/6)^20=.2139 Remember 4 less students and 1 less day
Wed: 4845(1/5)^4(4/5)^16=.2182
Thurs: 1820(1/4)^4(3/4)^12=.2252
Fri: 495(1/3)^4(2/3)^8=.2384
Sat: 70(1/2)^4(1/2)^4=.2734
Sun=1.000
Multiply all seven numbers = .0001445
.
Let me know if there is an easier way of doing this.
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Ed
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Probability-and-statistics/344705: Number of siblings per student in a preschool class
Number of siblings 0 1 2 3
Number of students 3 6 2 1
The table above shows how many students in a class of 12 preschoolers had 0, 1, 2, or 3 siblings.Later, a new student joined the class, and the average (arithmetic mean) number of siblings per student became equal to the median number of siblings per student. How many siblings did the new student have?
A. 0 B. 1 C. 2 D. 3 E. 4
1 solutions
Answer 246656 by edjones(7569) on 2010-09-18 10:38:17 (Show Source):
You can put this solution on YOUR website!3*0=0
6*1=6
2*2=4
1*3=3
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===>13/12=1.08 mean and 1 median at present.
If the new student has 0 siblings then the mean would be 13/13=1.0 and the median would still be one.
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Ed
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Triangles/343300: Please Help Me with this question!
The Length of one leg of an isosceles right triangle is 6 inches. Express the length of the hypotenuse in simplest radical form.
Thank you, in advance. 1 solutions
Answer 245638 by edjones(7569) on 2010-09-14 23:16:05 (Show Source):
You can put this solution on YOUR website!The sides of an isosceles right triangle are in the ratio: 1:1:sqrt(2) [SAT question!]
In this problem the the hypotenuse is 
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Ed
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Equations/343230: it says put each equation into standard form, if needed. Factor each equation and state the solutions. x square -6x + 34=5x+10 1 solutions
Answer 245624 by edjones(7569) on 2010-09-14 22:39:13 (Show Source):
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Linear-systems/343224: my problem is:
the sum of 3 numbers is 123. the second number is 9 less than two times the first number. the third number is 6 more than three times the first number. find the three number.
we are suppoed to make and equation and solve from there but i am not good at making an equations. i have tried to make many but none work.
thank you for helping me! 1 solutions
Answer 245622 by edjones(7569) on 2010-09-14 22:36:03 (Show Source):
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Polygons/343268: Draw a counterexample to show that this statement is false:"If a rectangle has perimeter 50 meters, then a pair of consecutive sides measures 10 meters and 15 meters." 1 solutions
Answer 245614 by edjones(7569) on 2010-09-14 22:13:42 (Show Source):
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Probability-and-statistics/342864: A file cabinet contains 3 blue and 6 red folders. If one folder is randomly selected, what is the probability of selecting:
A. A blue folder?
B. Either a red or a blue folder?
I got:
A: 3/9= 33.33%
B: 6/6= 100% Not sure if this one is right..If not, what are the correct steps? 1 solutions
Answer 245381 by edjones(7569) on 2010-09-14 09:58:42 (Show Source):
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Probability-and-statistics/342868: A file cabinet contains 3 blue and 6 red folders. If folders are randomly selected, "without replacement", what is the probability of selecting:
A. Two red folders?
B. Three blue folders?
C. The first folder blue and the second folder red?
D. A red and a blue folder?
I got:
A: 2/9= 22.22%
B: 3/7= 42.85%
C: 0 (because the blue folders were taken out with replacement?)
D: 0 (because again, there are no blue folders left?) 1 solutions
Answer 245374 by edjones(7569) on 2010-09-14 09:39:00 (Show Source):
You can put this solution on YOUR website!There is replacement between questions!
.
A: 6/9 * 5/8 = 5/12 or .4167
.
B: 3/9 * 2/8 * 1/7 = 1/84
OR
nCr=combination or n things taken r at a time.= n!/((n-r)!r!) (easier with larger numbers.)
3C3/9C3 = 1/84
.
C: 3/9 * 6/8 = 1/4
.
D: (6C1 + 3C1)/9C2
(6+3)/36 = 1/4
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Ed
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Rate-of-work-word-problems/342860: If it takes 4 people 6 hours to landscape a recreation area, how many hours will it take 3 people to complete the same task? 1 solutions
Answer 245373 by edjones(7569) on 2010-09-14 08:56:14 (Show Source):
You can put this solution on YOUR website!it takes 1 person 24 hrs to do the job
in 1 hr the person completes 1/24 the job.
3 * 1/24 = 1/8 the job in 1 hr with 3 people.
8 hrs it takes 3 people to complete the same task.
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Ed
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Probability-and-statistics/342373: A mathematics class is composed of 35 men and 45 women. There are 20 business majors, 30 biology majors, 10 computer science majors and 20 mathematics majors. No person has a double major. If a single student is chosen from the class, what is the probability that the student is a computer science or mathematics major? 1 solutions
Answer 245065 by edjones(7569) on 2010-09-13 13:29:13 (Show Source):
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Graphs/342395: Solve (for inequalities, write the solution in interval notation)
1. y/6-y/8=1
2. 3/5x>9 or 4x<-16
3. [2x-7]< 5 ( the sign is actually less than or equal to, i just didnt have a key to type it that way, and the brackets are actually absolute value signs) 1 solutions
Answer 245062 by edjones(7569) on 2010-09-13 13:14:28 (Show Source):
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