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QC42: GMAT PREP q
Please explain your ans
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shinewine
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shinewine wrote: QC42: GMAT PREP q
Please explain your ans
Here it goes...
Statement 1 is insuff. It only talks about S nothing about T.
Statement 2 is insuff. It talks about the sum, nothing about the median.
Taking these statements together, this is what i get.
S: median is 0.
integers are consecutive.
Therefore set S = {-2,-1,0,1,2}
T: same sum as S. S sums upto 0.
Therefore T sums upto 0.
integers are consecutive.
Therefore set S = {-3,-2,-1,0,1,2,3}
Median of Set S and Set T is 0. Therefore, equal.
Answer C.
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SuperHumanAmit wrote: shinewine wrote: QC42: GMAT PREP q
Please explain your ans Here it goes... Statement 1 is insuff. It only talks about S nothing about T. Statement 2 is insuff. It talks about the sum, nothing about the median. Taking these statements together, this is what i get. S: median is 0. integers are consecutive. Therefore set S = {-2,-1,0,1,2} T: same sum as S. S sums upto 0. Therefore T sums upto 0. integers are consecutive. Therefore set S = {-3,-2,-1,0,1,2,3} Median of Set S and Set T is 0. Therefore, equal. Answer C. i think Statement II is sufficient :
as i can thnk of only one case in which can furnish same sum for 5 and 7 consecutive intergers..
This when we have digits on either side of zero..as u ve correctly pointed out.. {-3,-2,-1,0,1,2,3}, {-2,-1,0,1,2}
can you think of some other case in whch sum of 7 and 5 conse. no.s is equal?
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If S={s,s+1,...,s+4} T={t,t+1,...,t+6}
For s+(s+1)+...(s+4)=t+(t+1)+...(t+6)
5s+10=7t+21
5s=7t+11
s=(7t+11)/5
if t=2, s=5
if t=7, s=12
So {5,6,7,8,9} and {2,3,4,5,6,7,8} have the same sum, but not the same median!
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Textbook style kevin. (E) is it!
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kevincan wrote: If S={s,s+1,...,s+4} T={t,t+1,...,t+6}
For s+(s+1)+...(s+4)=t+(t+1)+...(t+6)
5s+10=7t+21
5s=7t+11
s=(7t+11)/5
if t=2, s=5
if t=7, s=12
So {5,6,7,8,9} and {2,3,4,5,6,7,8} have the same sum, but not the same median!
thank you kevin..
i was almost thr..i calculated till 5s=7t+11...
.. but i could'nt get the appropriate values of s and t,
.
there is so much trial and error.. how did u click upon these values ? is thr any shortcut..
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gmatt73,
why is it E.. taken together, i would think C ..
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gk3.14 wrote: gmatt73,
why is it E.. taken together, i would think C ..
Consider two example sets
T={ -1, -2,0,1,2} -->median =0
S1={-3,-2, -1, 0,1,2,3} --> median=0
S2={ -5,-2,0,1,1,2,3} ---> median not equal to zero,
However, the sum of each of the sets, s1, s2 = sum of set T.
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aspirations:
but they have to be consecutive numbers.. so S2 has to be consecutive..that example does not work..
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gk3.14 wrote: aspirations:
but they have to be consecutive numbers.. so S2 has to be consecutive..that example does not work..
Exactly.
Answer should be C.
St1: S = {-2,-1,0,1,2}. No info about T.
St2:
Median equal for S = {-2,-1,0,1,2} T = {-3,-2,-1,0,1,2,3}
Median not equal for S = (5,6,7,8,9} T = {2,3,4,5,6,7,8}: INSUFF
Together:
S = {-2,-1,0,1,2} T = {-3,-2,-1,0,1,2,3} must be true.
Medians are equal.
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gk3.14 wrote: aspirations:
but they have to be consecutive numbers.. so S2 has to be consecutive..that example does not work..
Agreed, thanks for the catch, its C.
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I think it's B
S= {a,a+1,a+2,a+3,a+4}
T = {b,b+1,b+2,b+3,b+4,b+5,b+6)
Ok the way i see it is that it's a yes or no DS
1) is insuff for obvious reasons
Ok now it gets a bit tricky
We have to find it median of S = median of T
Inshort If a+2 = b+3 => a = b + 1
2) Says the sum of S (5a+10) = sum of T (7b + 16)
We get 5a + 10 = 7b + 16
Implying a = (7b + 6)/5 and not equal to b + 1 . Therefore B
Is there anything wrong with this method?
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jaypshah wrote: I think it's B
S= {a,a+1,a+2,a+3,a+4}
T = {b,b+1,b+2,b+3,b+4,b+5,b+6)
Ok the way i see it is that it's a yes or no DS
1) is insuff for obvious reasons
Ok now it gets a bit tricky
We have to find it median of S = median of T
Inshort If a+2 = b+3 => a = b + 1
2) Says the sum of S (5a+10) = sum of T (7b + 16)
We get 5a + 10 = 7b + 16
Implying a = (7b + 6)/5 and not equal to b + 1 . Therefore B
Is there anything wrong with this method?
going by ur calculation a=1.4b+1.2
how do u know that 0.4b is not equal to -0.2?
I think, C is the answer
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becasue B is an integer
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what does integer have to do with any of this?
the answer shud b C...
jaypshah wrote: becasue B is an integer
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good work guys. I myself picked B at first. Now I understand it
Heman
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missed "consecutive"  .... C it is ... what would I do if I do this the day after tomorrow  ((
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