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david01
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Kindly solve it with suitable logic......... 09 Jan 2010, 19:43
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Hello friends
I am facing problem with this question from last few days, it is a problem of algebra, I always use to visit on those sites which provides online GMAT prep, such as kaplan, TestCircle and many more to search out good problem.

If a+b = 12, and 1/a + 1/b= 6, then what should be the value of ab
(A) 1/2
(B) -3
(C) 2
(D) -2
(E) 1/6

If you kindly solve it then it will be a great help for me. I am looking for a good reply.
Thanks



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lagomez
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Kindly solve it with suitable logic......... 09 Jan 2010, 20:13
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david01
Hello friends
I am facing problem with this question from last few days, it is a problem of algebra, I always use to visit on those sites which provides online GMAT prep, such as kaplan, TestCircle and many more to search out good problems.

If a+b = 12, and 1/a + 1/b= 6, then what should be the value of ab
(A) 1/2
(B) -3
(C) 2
(D) -2
(E) 1/6

If you kindly solve it then it will be a great help for me. I am looking for a good reply.
Thanks
Show more

1/a + 1/b = 6
simplifying
a + b / ab = 6
a + b = 12 so you have

12/ab = 6
ab = 2
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styphen
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Kindly solve it with suitable logic......... 12 Jan 2010, 00:10
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Hello
It is given that 1/a + 1/b = 6
it means (a+b)/ab = 6
a+b = 12 is also given
so, 12/ab = 6
ab = 2
correct answer is (C) 2
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phoenixrulzz
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Kindly solve it with suitable logic......... 12 Jan 2010, 07:56
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1/a + 1/b = 6
so cross multiplying we get -
a+b/ab = 6 equation (1)
substituting value of a+b = 12 from question in equation 1 we get -
12/ab = 6
ab = 12/6
ab=2

option c



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Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
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