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by StarDust845 » Sun Jan 27, 2008 6:40 pm
In the fraction x/y, where x and y are positive integers, what i sthe value of y?

1) The least common denominator of x/y and 1/3 is 6.
2) x = 1
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by cris » Sun Jan 27, 2008 7:47 pm
This question is really confusing, "least common denominator" is not HCF or LCM...Least common denominator of anything should be 1...

Calista are you sure you copied that correctly??
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by malnv » Sun Jan 27, 2008 8:00 pm
Least Common denominator is usually applied to fractions. We unknowingly do L.C.D all the time when adding fractions

From the Q..

1. x/y + 1/3 has L.C.D. of 6 .
i.e. L.C.M (y,3) = 6 which gives y =2 (if the fraction is in reduced form)

But, x/y can be 2/4, which makes y =4..

So Not SUFF


2. x= 1, no way to find y.


Combining 1 & 2, y =2
SUFF

ANS: C

let me know if it matches with OA.
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by cris » Sun Jan 27, 2008 8:08 pm
we do the Least Common Multiple when adding fractions....

Correct me if i am wrong.
Last edited by cris on Sun Jan 27, 2008 10:42 pm, edited 3 times in total.
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by simplyjat » Sun Jan 27, 2008 8:55 pm
L.C.M (y,3) = 6 which gives y =2 (if the fraction is in reduced form)
This interpolation is incorrect y can be 6 as well...
simplyjat
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by malnv » Sun Jan 27, 2008 9:03 pm
You are right.. Its a possibility..

So combining 1 & 2, y can be either 2 or 6.

So it should be E.

Looks like i need to spend few seconds extra before i conclude :)

Thx for catching!
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by StarDust845 » Mon Jan 28, 2008 9:41 am
Yeah I too was confused with the question. But the question is correct and I think malnv's solution is good.

So rephrasing is LCD just LCM of denomitors?

Calista.
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by simplyjat » Mon Jan 28, 2008 10:22 pm
E is the correct answer for the question...
Thanks for updating the solution malnv
simplyjat
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