SOLUTION: For doing some work ganesh takes 10 days more than john.If both work together they completed the same work in 12 days.Find the number of days if ganesh walks alone

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Question 634850: For doing some work ganesh takes 10 days more than john.If both work together they completed the same work in 12 days.Find the number of days if ganesh walks alone
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=amount of time it takes John to do the work
Then John works at the rate of 1/x of the job per day
x+10=amount of time it takes Ganesh to do the work
Then Ganesh works at the rate of 1/(x+10) of the job per day
Together they complete the work in 12 days
So, together they work at the rate of 1/12 of the job per day
So our equation to solve is:
1/x +1/(x+10)=1/12 multiply each term by 12x(x+10)
12(x+10)+12x=x(x+10)
12x+120+12x=x^2+10x collecting like terms, we get
x^2-14x-120=0 quadratic in standard form and it can be factored
(x-20)(x+6)=0
x=20-----------------amount of time it takes John to do the work
x+10=20+10=30 days----ANSWER-- time it takes Ganesh working alone
and
x=-6---------------work is positive---no good
CK
1/20+1/30=1/12
3/60+2/60=1/12
5/60=1/12
1/12=1/12
Hope this helps---ptaylor