IMO B
s1) x+y=9
bth can have any values
s2) 52x+58y=492
only one set of value satisfy this condition
i.e x=5 and y=4
hence suff....
source pls kindly give the name of book .how many DS questions are there in the book and what is difficulty level
DS - Fastest solution?
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Source: Beat The GMAT — Data Sufficiency |
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thephoenix
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It is from the Veritas Prep Data Sufficiency workbook. Over a hundred problems.
How do you quickly determine:
How do you quickly determine:
This is where I struggled.s2) 52x+58y=492
only one set of value satisfy this condition
i.e x=5 and y=4
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thephoenix
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this was something called recognizing the pattern....
in my first attempt when i faced another version of same concept i went for C
but then when i understood the logic i made it a point in my flash card, which goes something like this
" in DS having two variable just find out whether they are int or not (this will either stated explicitly or implied as in this case) , typical statements will be (s1)x+y=some number and s2) Ax+by=$some value; since x and y are things such as some fruit ,items like pen book ....etc and they can not have a fractional value then just go for s2) in order to find the combintaion use s1 for limiting the values as here x+y will be 9 only and becoz x and y are int we have (1,8);(2,7);(3,6);(4,5)(5,4)(6,3)(7,2)(9,1)
using all these value in 2nd eqn you will come to know that only one set satisfy......
these are my findings
HTH
in my first attempt when i faced another version of same concept i went for C
but then when i understood the logic i made it a point in my flash card, which goes something like this
" in DS having two variable just find out whether they are int or not (this will either stated explicitly or implied as in this case) , typical statements will be (s1)x+y=some number and s2) Ax+by=$some value; since x and y are things such as some fruit ,items like pen book ....etc and they can not have a fractional value then just go for s2) in order to find the combintaion use s1 for limiting the values as here x+y will be 9 only and becoz x and y are int we have (1,8);(2,7);(3,6);(4,5)(5,4)(6,3)(7,2)(9,1)
using all these value in 2nd eqn you will come to know that only one set satisfy......
these are my findings
HTH
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gmatmachoman
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Man, I went for C & now I realised, B is sufficient. But we are so used 2 use 2 variable equations& tend to get "addicted" to that!thephoenix wrote:this was something called recognizing the pattern....
in my first attempt when i faced another version of same concept i went for C
but then when i understood the logic i made it a point in my flash card, which goes something like this
" in DS having two variable just find out whether they are int or not (this will either stated explicitly or implied as in this case) , typical statements will be (s1)x+y=some number and s2) Ax+by=$some value; since x and y are things such as some fruit ,items like pen book ....etc and they can not have a fractional value then just go for s2) in order to find the combintaion use s1 for limiting the values as here x+y will be 9 only and becoz x and y are int we have (1,8);(2,7);(3,6);(4,5)(5,4)(6,3)(7,2)(9,1)
using all these value in 2nd eqn you will come to know that only one set satisfy......
these are my findings
HTH
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thephoenix
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Gmat is a game of recognizing the pattern , if we devlop this quality then half of battle is won without any extra effortgmatmachoman wrote: Man, I went for C & now I realised, B is sufficient. But we are so used 2 use 2 variable equations& tend to get "addicted" to that!
