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Recent problems solved by 'edjones'

edjones answered: 7568 problems
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Probability-and-statistics/376713: If 29 tickets are sold and 2 prizes are to awarded, find the probability that one person will win 2 prizes if that person buys 2 tickets. Enter your answer as a fraction or as a number rounded to three decimal places. 1 solutions Answer 267994 by edjones(7569)   on 2010-11-27 23:02:39 (Show Source): You can put this solution on YOUR website! 2/29 * 1/28 = 1/406 . Ed

Geometry_Word_Problems/376526: How do I properly solve this FOILING problem? -6rs^2(3r-2s-3) 1 solutions Answer 267890 by edjones(7569)   on 2010-11-27 14:05:59 (Show Source): You can put this solution on YOUR website! This is not a FOIL problem. Multiply -6rs^2 times each number individually.

Linear-equations/376541: Hi Need help solving this problem!! x – 2y = –9 x + 3y = 16 1 solutions Answer 267888 by edjones(7569)   on 2010-11-27 14:00:46 (Show Source): You can put this solution on YOUR website! do you want to solve for x or y?

Radicals/376531: √5x-1 = 10 1 solutions Answer 267887 by edjones(7569)   on 2010-11-27 13:58:59 (Show Source): You can put this solution on YOUR website! sqrt(5x-1)=10 5x-1=100 square each side. 5x=101 x=101/5 . Ed

Equations/376540: Which of the following systems has (5,2) as a solution? I.) 3x + y = 1 2x + 3y = -11 II.) 4x + 3y = 26 3x + 7y = 29 1 solutions Answer 267885 by edjones(7569)   on 2010-11-27 13:54:23 (Show Source): You can put this solution on YOUR website! replace x with 5 and y with 2 to find which gives the correct answer. . Ed

Probability-and-statistics/376507: * A lot of 75 washers contains five in which the variability in thickness around the circumference of the washer is unacceptable. A sample of 10 washers is selected at random, without replacement. i) What is the probability that at least one unacceptable washer is in the sample? ii) What is the probability that at most one unacceptable washer is in the sample? 1 solutions Answer 267850 by edjones(7569)   on 2010-11-27 12:27:13 (Show Source): You can put this solution on YOUR website! This is a hypergeometric distrribution. i) 1-(70C10/75C10) =1-.4786 =0.5214 . ii) (70C10 + (70C9 * 5C1))/75C10 =.8708 . Ed

Probability-and-statistics/376335: 1. an ice chest contains 3 cans of apple juice, 5 cans of grape juice, 8 cans of orange juice and 2 cans of pineapple juice. You randomly select 3 cans succession. find the probability of selecting no grape juice? 2. the winner of a raffle will receive a new car. If 10,000 raffle tickets were sold and you purchased 25 tickets, what are the odds against your winning the car? 3. If you are given odds 3 to 7 in favor of winning a bet, what is the probability of winning the car? 1 solutions Answer 267759 by edjones(7569)   on 2010-11-26 20:17:23 (Show Source): You can put this solution on YOUR website! 3. 7+3=10 3/10 . Ed

Quadratic_Equations/376338: how do i write a quadratic expression from the answer, the answer being; - sqrt(5), 6 sqrt(5) ?? please demonstrate so i can learn this. 1 solutions Answer 267755 by edjones(7569)   on 2010-11-26 20:11:38 (Show Source): You can put this solution on YOUR website! x=-sqrt(5), x=6sqrt(5) (x+sqrt(5))(x-6sqrt(5))=0 f(x)=x^2-5sqrt(5)x-30 FOIL

Probability-and-statistics/376332: if you are dealt 5 cards from a deck of 52 cards, find the probability that all 5 cards are picture cards 1 solutions Answer 267753 by edjones(7569)   on 2010-11-26 20:05:54 (Show Source): You can put this solution on YOUR website! nCr=Cobination of n things taken r at a time=n!/((n-r)!r!) There are 12 picture cards in a deck. 12C5/52C5 =792/2598960 =.0003047

decimal-numbers/376204: like how do you round the numbers and then get x and 0 and things? 1 solutions Answer 267749 by edjones(7569)   on 2010-11-26 19:56:48 (Show Source): You can put this solution on YOUR website! Submit problems you are having trouble with and we will answer them.

Probability-and-statistics/376250: In an urn there are several color marbles, 8blue, 11white, 6yellow, 6red. You are to choose 5 marbles randomly. What is the probability that 4 or more are white marbles? (Please note step by step) 1 solutions Answer 267742 by edjones(7569)   on 2010-11-26 19:44:01 (Show Source): You can put this solution on YOUR website! 8+11+6+6=31 marbles total. nCr=Combination of n things taken r at a time=n!/((n-r)!r!) . (11C4*20C1 + 11C5)/31C5 =((330*20)+462)/169911 =(6600+462)/169911 =7062/169911 =0.0416 . Ed

Probability-and-statistics/376285: The probability that a given tourist goes to amusement park is 0.47, and the probability that she goes to the water park 0.58. if the probabitiy that she goes to either the water park or the amusement park is 0.95, what is the probability that she visit both of the parks on vacation 1 solutions Answer 267734 by edjones(7569)   on 2010-11-26 19:25:09 (Show Source): You can put this solution on YOUR website! A + W - (A n W) = A U W .47+.58-x=.95 x=.10 the probability that she visit both of the parks on vacation. . Ed

Probability-and-statistics/376318: if you draw 2 clubs on 2 consecutive draws from a standard deck of cards you win $23 otherwise you pay me $3 cards drawn without replacement enter the expected value of proposition 1 solutions Answer 267727 by edjones(7569)   on 2010-11-26 19:09:42 (Show Source): You can put this solution on YOUR website! 13/52 * 12/51 = 1/17 16*-3=-48 23*1 =23 ----------add =====>-$25. expected value of proposition. . Ed

Probability-and-statistics/376288: Cable Television In 2006, 86% of U.S. households had cable TV. Choose 3 households at random. Find the probability that a. None of the 3 households had cable TV b. All 3 households had cable TV c. At least 1 of the 3 households had cable TV 1 solutions Answer 267725 by edjones(7569)   on 2010-11-26 19:03:00 (Show Source): You can put this solution on YOUR website! Let x=.86, y=.14 (x+y)^3 Binomial expansion. . a) y^3=.0027 . b) x^3=.6361 . c)1-y^3=1-.0027=.9973 . Ed

Probability-and-statistics/376315: The senate in a certain state is compromised of 54 republicans, 44 democrats, and 2 independents? How many commities can be formed if there has to be 5 republicans and 2 democrats? 1 solutions Answer 267723 by edjones(7569)   on 2010-11-26 18:55:58 (Show Source): You can put this solution on YOUR website! 54C5 * 44C2 * 2C0 =3162510*946 =2,991,734,460 . Ed

Probability-and-statistics/375906: Elaine is 65 years old, and has the probability that she will be alive in 10 years is 76%. John is 35, and the probability that he will be alive in 10 years is 90%. What is the brobability they will be both alive in 10 years? 1 solutions Answer 267454 by edjones(7569)   on 2010-11-25 08:14:00 (Show Source): You can put this solution on YOUR website! .76 * .90 = .684 . Ed

Probability-and-statistics/375910: in a school,45% of the students are boys and 55% are girls. in this school, 12% of the boys are left handed and 9% of the girls are left handed. a student is to be chosen at random using a tree diagram a) calculate the probability that the student is not left handed Given that the student chosen is left handed, b)calculate, to 3 significant figures,the probabillity that the student is a girl 1 solutions Answer 267453 by edjones(7569)   on 2010-11-25 08:11:03 (Show Source): You can put this solution on YOUR website! We can't do tree diagrams on this site. . a) (.45*.88)+(.55*.91)=.8965 . b) .45*.12=.0540 LHB .55*.09=.0495 LHG ---------------- =======>.1035 Total LH . .0495/.1035 = .478 Given that the student chosen is left handed, the probabillity that the student is a girl. . Ed

Probability-and-statistics/375961: in a online survey for talbots of 1095 women ages 35 yr and older the participants were asked what article of clothing women most want to fit perfectly a summary of the results of thesurvey follows article of clothing responedents jeans 470 black pantsuit 307 cocktail dress 230 white shirt 22 gown 11 other 55 if a women who participated in the survey is chosen at random what is the probabality that she most wants A) jeans to fit perfectly or b) a black paintsuit,or cocktail dress to fit perfectly 1 solutions Answer 267451 by edjones(7569)   on 2010-11-25 07:46:13 (Show Source): You can put this solution on YOUR website! jeans 470 black pantsuit 307 cocktail dress 230 white shirt 22 gown 11 other 55 ----------add ====> 1,095 Total . a) 470/1095 = 94/219 . b) (307+230)/1095 =179/365 . Ed

Probability-and-statistics/376017: USA Today reports that about 25% of all prison parolees become repeat offenders. Alice is a social worker whose job is to counsel people on parole. Let us say success means a person does not become a repeat offender. Alice has been given a group of four parolees. (a) Find the probability P(r) of r successes ranging from 0 to 4. (b) What is the expected number of parolees in Alice's group who will not be repeat offenders? What is the standard deviation? 1 solutions Answer 267449 by edjones(7569)   on 2010-11-25 07:31:34 (Show Source): You can put this solution on YOUR website! let x=.75 and y=.25 (x+y)^4 Binomial distribution. . a) x^4=.3164 P(4) 4x^3y=.4219 6x^2y^2=.2109 4xy^3=.0469 y^4=.0039 P(0) . b) mean=n*p=4*.75=3 the expected number of parolees in Alice's group who will not be repeat offenders. Standard deviation=sqrt(np(1-p)) =sqrt(4*.75*.25) =sqrt(.75) =0.8660 . Ed

Numeric_Fractions/376033: find a number such that nine added to two times the number is equal to the product of the number and the quantity of one added to the number 1 solutions Answer 267441 by edjones(7569)   on 2010-11-25 06:42:53 (Show Source): You can put this solution on YOUR website! 2x+9=x(x+1) 2x+9=x^2+x x^2-x-9=0 Solved by pluggable solver: SOLVE quadratic equation with variable Quadratic equation (in our case ) has the following solutons: For these solutions to exist, the discriminant should not be a negative number. First, we need to compute the discriminant : . Discriminant d=37 is greater than zero. That means that there are two solutions: . Quadratic expression can be factored: Again, the answer is: 3.54138126514911, -2.54138126514911. Here's your graph: . Ed

Probability-and-statistics/375981: A dart is thrown randomly and stick on the circular dart board with 26 partitions. determine the probability that the dart lands on the area marked with a number greater than four and less than or equal to 13. 1 solutions Answer 267399 by edjones(7569)   on 2010-11-24 22:24:10 (Show Source): You can put this solution on YOUR website! There are 9 numbers greater than four and less than or equal to 13. 9/26 Probability.

Permutations/376002: A& B are two players. They need to select one number from 1 to 25. If both the players select the same numbers they will win the prize. What is the probability of not winning in a single trial? 1 solutions Answer 267398 by edjones(7569)   on 2010-11-24 22:19:53 (Show Source): You can put this solution on YOUR website! 24/25

Probability-and-statistics/375582: The Sad State Lottery requires you to select a sequence of three different numbers from zero through 53. (Order is important.) You are a winner if your sequence agrees with that in the drawing, and you are a booby prize winner if your selection of numbers is correct, but in the wrong order. (Round all answers to three significant figures. Enter the answers in scientific notation.) What is the probability of being a winner? 1 What is the probability of being a booby prize winner? 2 What is the probability that you are either a winner or a booby prize winner? 3 1 solutions Answer 267168 by edjones(7569)   on 2010-11-24 01:18:26 (Show Source): You can put this solution on YOUR website! nPr=n!/(n-r)! . 1) nPr=n!/(n-r)! 1/(53!/(53-3)!)=1/140,556 . 2) nCr=n!/((n-r)!r!) 1/(53!/(50!*3!))-(53!/(53-3)!) =1/23,426 - 1/140556 =6/140556 - 1/140556 =5/140556 . 3) 5/140556 + 1/140,556 =6/140,556 . Ed

Money_Word_Problems/375578: Suzy has a bag containing 2 red marbles, 2 green ones, 5 white ones, and 5 purple ones. She grabs 7 of them. Find the probability that she has all red ones. Express the answer as a fraction in lowest terms. 1Your answer is incorrect. 1 solutions Answer 267166 by edjones(7569)   on 2010-11-24 01:04:11 (Show Source): You can put this solution on YOUR website! She can't possibly have all red ones. There are only 2 red ones and she took 7.

Rate-of-work-word-problems/375331: a mason's helper requires 4 hours more to pave a concrete walk than it takes the mason. the two worked together for 3 hours when the mason war called away. the helper completed the job in 2 hours. how long would it take each to do the same job working alone? 1 solutions Answer 267034 by edjones(7569)   on 2010-11-23 15:09:23 (Show Source): You can put this solution on YOUR website! Mason does job in m hours. Helper does job in m+4 hours. t=time in hrs 1/m + 1/(m+4)=(2m+4)/(m^2+4m) = 1/t 3 * (2m+4)/(m^2+4m) = (6m+12)/(m^2+4m) = 3/t 1 - (6m+12)/(m^2+4m) time remaining [1 - 3/t] 2 * 1/(m+4)= 1 - (6m+12)/(m^2+4m) 2/(m+4)=1 - (6m+12)/(m(m+4)) 2m=m^2+4m-6m-12 m^2-4m-12=0 (m-6)(x+2)=0 m=6 hr m+4=10 hr . Ed

Probability-and-statistics/375313: Question1.In a college class of 100 students,54 studied mathmatics,69 studied history,and 35 studied both mathmatics and history.if one of these students is selected at random,find the probability that. a.the student takes mathmatics or history b.the student does not take either of these subjects c.the student takes history but not mathmatics 1 solutions Answer 267001 by edjones(7569)   on 2010-11-23 13:17:37 (Show Source): You can put this solution on YOUR website! Make a Venn Diagram so you understand this! M=math, H=history, M'=non math, U=union, n=intersection . a) M U H = (19+35+34)/100 = 88/100 = 22/25 . b) M' n H' = (100-88)/100 = 12/100 = 3/25 . c) H n M' = 34/100 = 17/50 . Ed

Equations/375339: a) {x + 3y = 42 { x = 4y _________________ b) { x + 16y = 24 {2x - 16y = 12 _________________ c) {4x + y = 10 {5x - 3y = 9 _________________ d) {3x + 5y = 1 {6x + 3y = 2 _________________ e) { 4p - 3q = 9 { -3p + 2q = -5 _________________ f) {3c + 12d = 4 {2c + 8d = -3 _________________ g) {5x + 4 (y - 5) = x + 8 (x = 2 (y+1) - 4 _________________ h) {y = 2x + y { y = -3x + 1 1 solutions Answer 266989 by edjones(7569)   on 2010-11-23 12:31:32 (Show Source): You can put this solution on YOUR website! x + 3y = 42 x = 4y 4y+3y=42 7y=42 y=6 x=24 . Ed

test/375369: Equations. 4a-(3-a)=17. 2=5(5z-2)-9(3z-2) 1 solutions Answer 266985 by edjones(7569)   on 2010-11-23 12:26:28 (Show Source): You can put this solution on YOUR website! 5(5z-2)-9(3z-2)=2 25z-10-27z+18=2 -2z=-6 z=3 . Ed

test/375371: 4a-(3-a)=17 2=5(5z-2)-9(3z-2) 1 solutions Answer 266982 by edjones(7569)   on 2010-11-23 12:22:21 (Show Source): You can put this solution on YOUR website! 4a-(3-a)=17 4a-3+a=17 5a=20 a=4 . Ed

Distributive-associative-commutative-properties/375392: what is b+0=b identity communitive associative distributive or zero property 1 solutions Answer 266981 by edjones(7569)   on 2010-11-23 12:19:40 (Show Source): You can put this solution on YOUR website! zero property

Polynomials-and-rational-expressions/375396: (√c-√d)/(√c+√d) Rationalize the denominator. Assume that all expressions under radicals represent positive numbers. Help? 1 solutions Answer 266978 by edjones(7569)   on 2010-11-23 12:17:30 (Show Source): You can put this solution on YOUR website! (√c-√d)/(√c+√d) (sqrt(c)-sqrt(d))/sqrt(c)+sqrt(d) * (sqrt(c)-sqrt(d))/(sqrt(c)-sqrt(d)) =(x-2sqrt(x)sqrt(y)+y)/(x-y) . Ed