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edjones answered: 7568 problems
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Percentage-and-ratio-word-problems/346146: 1. A management consulting firm recommends that the ratio of midmanagement salaries to junior management salaries be 7:5. Using this recommendation, find the yearly midmanagement salary when the junior management salary is $90,000.
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) About Me  on 2010-09-21 15:03:30 (Show Source):
You can put this solution on YOUR website!
3/36=1/12
I he lost 1/12 his goal in 5 wks then in 12*5=60 wks he will reach his goal.


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) About Me  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
.
(18.75+26.25+6.25)/60
=51.25/60
=.8542 the probability that the selected student is female or a senior.
.
Ed


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) About Me  on 2010-09-21 14:33:17 (Show Source):


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) About Me  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.
.
Ed


Inequalities/346053: (2x-4)/7 < = x+3
1 solutions

Answer 247516 by edjones(7569) About Me  on 2010-09-21 12:36:14 (Show Source):
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(2x-4)/7 < = x+3
2x-4<=7x+21
-5x<=25
x>=-5 Remember to reverse the inequality sign.
.
Ed


Numbers_Word_Problems/344718: x/(5x-25) - 2 = x/(x-5) simplify and solve for x
1 solutions

Answer 246663 by edjones(7569) About Me  on 2010-09-18 11:00:28 (Show Source):
You can put this solution on YOUR website!
x/(5x-25) - 2 = x/(x-5)
x/5(x-5) - 2 = x/(x-5)
x-2(5x-25)=5x Multiply each side by 5(x-5)
x-10x+50=5x
-14x=-50
x=50/14
=25/7
.
Ed


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) About Me  on 2010-09-18 10:38:17 (Show Source):
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3*0=0
6*1=6
2*2=4
1*3=3
-----
===>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.
.
Ed


Square-cubic-other-roots/344604: x^2-y^6
1 solutions

Answer 246654 by edjones(7569) About Me  on 2010-09-18 10:23:08 (Show Source):
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x^2-y^6
(x+y^3)(x-y^3)
.
Ed


Quadratic_Equations/343955: Sove for F: r = sqrt kq1q2/ sqrt F
Thank you so much!
1 solutions

Answer 246059 by edjones(7569) About Me  on 2010-09-16 10:27:27 (Show Source):
You can put this solution on YOUR website!
r = sqrt kq1q2/ sqrt F
sqrt(F)=sqrt kq1q2/r


Travel_Word_Problems/343945: 2 long books containing a total of 2,400 pages have a ratio of 3:5 how many pages are in each book?
1 solutions

Answer 246055 by edjones(7569) About Me  on 2010-09-16 10:19:22 (Show Source):
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3/8 * 2400 = 900 pages
5/8 * 2400 = 1500n pages
.
Ed


Money_Word_Problems/343951: 100 item for 16.99 each how much is that
1 solutions

Answer 246052 by edjones(7569) About Me  on 2010-09-16 10:14:32 (Show Source):


Linear-equations/343285: how do I graph (0,2), m=0
1 solutions

Answer 245639 by edjones(7569) About Me  on 2010-09-14 23:21:48 (Show Source):
You can put this solution on YOUR website!
Since it has no slope, it is a horizontal line, where y=2.


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) About Me  on 2010-09-14 23:16:05 (Show Source):
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The sides of an isosceles right triangle are in the ratio: 1:1:sqrt(2) [SAT question!]
In this problem the the hypotenuse is 6sqrt%282%29
.
Ed


Polynomials-and-rational-expressions/343301: The top of a 15ft ladder is 3ft farther up a wall than the foot of the ladder is from the bottom of the wall. How far is the foot of the ladder from the bottom of the wall?
1 solutions

Answer 245636 by edjones(7569) About Me  on 2010-09-14 23:04:46 (Show Source):
You can put this solution on YOUR website!
The ladder is the hypotenuse of a right triangle with a base x and altitude x+3.
x^2+(x+3)^2=15^2
x^2+x^2+6x+9=225
2x^2+6x-116=0
x^2+3x-58=0
x=6.262...' see below
.
Ed
.
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B3x%2B-58+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%283%29%5E2-4%2A1%2A-58=241.

Discriminant d=241 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-3%2B-sqrt%28+241+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%283%29%2Bsqrt%28+241+%29%29%2F2%5C1+=+6.26208734813001
x%5B2%5D+=+%28-%283%29-sqrt%28+241+%29%29%2F2%5C1+=+-9.26208734813001

Quadratic expression 1x%5E2%2B3x%2B-58 can be factored:
1x%5E2%2B3x%2B-58+=+1%28x-6.26208734813001%29%2A%28x--9.26208734813001%29
Again, the answer is: 6.26208734813001, -9.26208734813001. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B3%2Ax%2B-58+%29


Polynomials-and-rational-expressions/343242: Find a polynomial with integer coefficients that satisfies the given conditions.
Q has degree 3 and zeros −9and 1 + i.
1 solutions

Answer 245629 by edjones(7569) About Me  on 2010-09-14 22:47:10 (Show Source):
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x=-9, x=1+i, x=1-i
(x+9)(x-(1+i)(x-(1-i)
=x^3+7x^2-16x+18
.
Ed


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) About Me  on 2010-09-14 22:39:13 (Show Source):
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-6x + 34=5x+10
-11x=-24
x=24/11


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) About Me  on 2010-09-14 22:36:03 (Show Source):
You can put this solution on YOUR website!
Let the numbers be x, y, & z.
x+y+z=123
y=2x-9
z=3x+6
.
x+2x-9+3x+6=123
6x=126
.
x=21
y=33
z=69
.
Ed


Polygons/343262: The perimeter of an equilateral octagon is 42 cm.
Find the length of each side.
1 solutions

Answer 245615 by edjones(7569) About Me  on 2010-09-14 22:15:50 (Show Source):


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) About Me  on 2010-09-14 22:13:42 (Show Source):
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draw a rectangle with sides of 5 and 20.


Expressions-with-variables/343275: If I subtract a number from 3 less than 5 times that same number I would get 165. What is the number? (equation and answer needed)
1 solutions

Answer 245613 by edjones(7569) About Me  on 2010-09-14 22:10:25 (Show Source):
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5x-3-x=165
4x=168
x=42
.
Ed


Quadratic_Equations/343276: 5x2 = -10x - 2
1 solutions

Answer 245612 by edjones(7569) About Me  on 2010-09-14 22:07:29 (Show Source):
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5x2 = -10x - 2
5x^2+10x+2=0
x=-1-(sqrt(15)/5), x=-1+sqrt(15)/5 See below
.
Ed
.
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 5x%5E2%2B10x%2B2+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%2810%29%5E2-4%2A5%2A2=60.

Discriminant d=60 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-10%2B-sqrt%28+60+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%2810%29%2Bsqrt%28+60+%29%29%2F2%5C5+=+-0.225403330758517
x%5B2%5D+=+%28-%2810%29-sqrt%28+60+%29%29%2F2%5C5+=+-1.77459666924148

Quadratic expression 5x%5E2%2B10x%2B2 can be factored:
5x%5E2%2B10x%2B2+=+5%28x--0.225403330758517%29%2A%28x--1.77459666924148%29
Again, the answer is: -0.225403330758517, -1.77459666924148. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+5%2Ax%5E2%2B10%2Ax%2B2+%29


Age_Word_Problems/342852: TWO BROTHERS HAVE A TOTAL AGE OF 3 YEARS.ONE IS 2 YEARS OLDER THAN THE OTHER.WHAT ARE THERE AGES
1 solutions

Answer 245383 by edjones(7569) About Me  on 2010-09-14 10:05:31 (Show Source):
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Let a be the age of the elder.
a+b=3
a-b=2
------add
2a=5
a=5/2= 2 1/2 yrs old
b= 6 months old
.
Ed


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) About Me  on 2010-09-14 09:58:42 (Show Source):
You can put this solution on YOUR website!
You answers are correct but B should be 9/9=100%


absolute-value/342863: What is the absolute value of the difference between the solutions of the equation
|2 + (p/3)| = 5 ?
1 solutions

Answer 245379 by edjones(7569) About Me  on 2010-09-14 09:54:52 (Show Source):
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|2 + (p/3)| = 5
.
2 + p/3 = 5
6+p=15
p=9
.
2 + p/3 = -5
6+p=-15
p=-21
.
|9-(-21)|=30
|-21-9|=30
.
Ed


Radicals/342867: If √(4x + 3) = 3√(x- 8), then what is the value of x?
1 solutions

Answer 245377 by edjones(7569) About Me  on 2010-09-14 09:46:03 (Show Source):
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√(4x + 3) = 3√(x- 8)
4x+3=9(x-8) Square each side.
4x+3=9x-72
5x=75
x=15
.
Ed


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) About Me  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
.
Ed


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) About Me  on 2010-09-14 08:56:14 (Show Source):
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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.
.
Ed


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) About Me  on 2010-09-13 13:29:13 (Show Source):
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80 people
(10+20)/80
=3/8 the probability that the student is a computer science or mathematics major.
.
Ed


Probability-and-statistics/342389: find each percent change to the nearest percent. state if it is an increase or decrease.
QUESTION 1:
1] From 45ft to 92ft.
QUESTION 2:
2] from 74 hours to 85 hours.
1 solutions

Answer 245064 by edjones(7569) About Me  on 2010-09-13 13:22:02 (Show Source):
You can put this solution on YOUR website!
(92/45 * 100) -100
=104% increase
.
(85/74 * 100)-100
=15% increase
.
Ed


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) About Me  on 2010-09-13 13:14:28 (Show Source):
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[2x-7]<= 5
.
2x-7<5
2x<12
x<=6
.
2x-7>=-5
2x>2
x>1
.
Ed


Divisibility_and_Prime_Numbers/342234: 39,175 / 207
1 solutions

Answer 244952 by edjones(7569) About Me  on 2010-09-13 03:37:56 (Show Source):