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Set S consists of 5 consecutive integers and set T consists [#permalink]
05 Sep 2008, 08:58
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Set S consists of 5 consecutive integers and set T consists of 7 consecutive integers. Is median of set S equal to the median of set T ?
1) Median of set S is 0 2) Sum of the numbers in S is equal to the sum of numbers in T
Haven't figured out the explanation for this yet..
'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 09:07
i guess that the ans for the first one is B.
stat 1) -2,-1,0,1,2 and 2,3,4. here median are not same suppose from the first set, -2 and 2 were removed the median would be the same i.e if the other set was -1,0,1. insuff
stat2) the only way i can figure out that two sets having different no. of consecutive elemts have same sum, is if the median is zero. suff.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 09:47
Set S consists of 5 consecutive integers and set T consists of 7 consecutive integers. Is median of set S equal to the median of set T ?
1) Median of set S is 0 2) Sum of the numbers in S is equal to the sum of numbers in T
1) is not sufficient
For 2) let S = {m-2,m-1,m,m+1,m+2} and T = {n-3,n-2,n-1,n,n+1,n+2,n+3}
sum of no.s in S = 5m sum of no.s in T = 7n
5m = 7n works for m = 7 and n =5 and for m=n=0.
Not sufficient.
Take both 1) and 2). 1) says m = 0. Therefore n = 0.
Answer is C.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 10:22
Good job!! eyunni Great approach.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 10:30
bhushangiri wrote: Haven't figured out the explanation for this yet..
'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks. Better way for this approach is draw a picture. 1) The distance between r and 0 is three times the distance between m and 0 ________m_____0__________r____ __r______m____ 0______________ not suffcient 2) ________m_____0____12__________r____ _______________0__m_________12__________r____ ____________r___0___12__________m____ combined. ________m_____0____12__________r____ _______________0__m_________12__________r____ not suffcient E what is OA.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 10:42
x2suresh wrote: bhushangiri wrote: Haven't figured out the explanation for this yet..
'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks. Better way for this approach is draw a picture. 1) The distance between r and 0 is three times the distance between m and 0 ________m_____0__________r____ __r______m____ 0______________ not suffcient 2) ________m_____0____12__________r____ _______________0__m_________12__________r____ ____________r___0___12__________m____ combined. ________m_____0____12__________r____ _______________0__m_________12__________r____ not suffcient E what is OA. Ya.. this approach is better than the algebraic approach which got me wrong. thanx.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 13:38
x2suresh wrote: bhushangiri wrote: Haven't figured out the explanation for this yet..
'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks. Better way for this approach is draw a picture. 1) The distance between r and 0 is three times the distance between m and 0 ________m_____0__________r____ __r______m____ 0______________ not suffcient 2) ________m_____0____12__________r____ _______________0__m_________12__________r____ ____________r___0___12__________m____ combined. ________m_____0____12__________r____ _______________0__m_________12__________r____ not suffcient E what is OA. I don't get the first drawing for the combined tacit. How can m be negative and 12 still be between m and r? is it if m is like -12 and r would be 36 then? thanks.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 14:01
'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks.[/quote]
I'm new here, but tackling this one I'm come up with both together are sufficient. I threw numbers in to solve the problem.
We know r = 3m
|-------m-------12--------3m 0
I plugged in a few numbers and found that if you plug in 6 for m, you get
|-----6------12------18 0
18 = 3 x 6, and 12 works as the midpoint. No other values will work here, so to me that answers the question. If I'm missing something- please let me know!
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 14:46
NickTW wrote: 'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks. I'm new here, but tackling this one I'm come up with both together are sufficient. I threw numbers in to solve the problem. We know r = 3m |-------m-------12--------3m 0 I plugged in a few numbers and found that if you plug in 6 for m, you get |-----6------12------18 0 18 = 3 x 6, and 12 works as the midpoint. No other values will work here, so to me that answers the question. If I'm missing something- please let me know![/quote] 1) |r| = |3m| Insuff 2) |m| + |r| / 2 = 12 Insuff ( -12 & 36 mid point is 12, 6 and 18 mid point is 12 ) Together 4 |m| =24 means m = +6 or -6 r= + 18 or -18 clearly (6,18) fits the bill. (-6,18) mid point is 6; (-6, -18) mid point is -12. (6, -18) midpoint is -6 We can say r=18 is OA C??
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 14:47
OAs
Q1 - c Q2 - e
Thanx for all the suggestions folks..
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 18:28
Set S consists of 5 consecutive integers and set T consists of 7 consecutive integers. Is median of set S equal to the median of set T ? 1) Median of set S is 0 2) Sum of the numbers in S is equal to the sum of numbers in T Haven't figured out the explanation for this yet.. bhushangiri wrote: 'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 18:30
Set S consists of 5 consecutive integers and set T consists of 7 consecutive integers. Is median of set S equal to the median of set T ? 1) Median of set S is 0 2) Sum of the numbers in S is equal to the sum of numbers in T Haven't figured out the explanation for this yet.. bhushangiri wrote: 'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
thanks folks. is that the no. zero or the letter O ? i considerd it as 0 and solved. kindly clarify
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 18:46
IMO C.
1 ) Median of set S is 0 => does not say anything about T
2 ) Sum of the numbers in S is equal to the sum of numbers in T => infact this one is tempting..because we know that the mean and median for continous sequence is same.. so if X is the sum of the series, then median of S and T is X/5 and X/7 respectively,, so that means they are not equal,, but wait what if X=0 so, 2 is not sufficient.
Including 1 and 2 ; median of S = 0,, so X=0 and so median of T=0
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 19:03
For the second question : IMO E
1) The distance between r and 0 is three times the distance between m and 0 => r=3m or r=-3m.. not sufficient 2) 12 is halfway between m and r = > 12-m=r-12 = > not suffient as we have only one expression for 2 varaibles.
conbined.. if r=3m , from 12-m=r-12 => 24=4m=> m=6 and r=18 if r=-3m, from 12-m=r-12 => 2m=-24=> m -12 and r= 36 so, we are not sure.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 19:48
good method ssandeepan... i was just thinking abt solving it algebraically,when i saw your post . good method and nicely posted.
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 19:52
bhushangiri wrote: Set S consists of 5 consecutive integers and set T consists of 7 consecutive integers. Is median of set S equal to the median of set T ?
1) Median of set S is 0 2) Sum of the numbers in S is equal to the sum of numbers in T
Haven't figured out the explanation for this yet..
'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks. Q1) given : S{5 consec integers},T{7 consecutive integers} Question: MEDs=MEDt ? 1) Median of set S is 0 ->its INSUFFI since 7 cosecutive integers can be anywhere ,MEDt canbe 0 if all integers are about 0 (0 as median) or they can be scattered somewhere else on the number line with different median. 2) Sum of the numbers in S is equal to the sum of numbers in T -> sum of 5 consecutive numbers = sum of 7 consec numbers say S={n-2,n-1,n,n+1,n+2} T={p-3,p-2,p-1,p,p+1,p+2,p+3} 5n=7p => if n=p=0 then only true for n and p o be integers . hence SUFFI mean =0 for both and hence equal. IMO B Q2)given :'m' and 'r' are two numbers on the number line. question :r=? (1) The distance between r and 0 is three times the distance between m and 0 -> r and m can be on diffrent sides on the number line,r can be +ve or r can be -ve INSUFFICIENT ,again m can be any value (integer ,fraction etc). 2) 12 is halfway between m and r. =>again r ad m can be on same side of 0 or different side then different values of r.again m can be inteer ,fraction ,and r too can be .INSUFFI (1) and (2) => is not SUFFI since both of them dont say about value of m whether integer or fraction and also no value of m ,hence for every value of m there can be a value for r even if 12 lies in between.INSUFFI IMO E
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Re: Two GMAT prep DS questions [#permalink]
05 Sep 2008, 19:58
eyunni wrote: Set S consists of 5 consecutive integers and set T consists of 7 consecutive integers. Is median of set S equal to the median of set T ?
1) Median of set S is 0 2) Sum of the numbers in S is equal to the sum of numbers in T
1) is not sufficient
For 2) let S = {m-2,m-1,m,m+1,m+2} and T = {n-3,n-2,n-1,n,n+1,n+2,n+3}
sum of no.s in S = 5m sum of no.s in T = 7n
5m = 7n works for m = 7 and n =5 and for m=n=0.
Not sufficient.
Take both 1) and 2). 1) says m = 0. Therefore n = 0.
Answer is C. Good one,i just missed on the values !!!
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Re: Two GMAT prep DS questions [#permalink]
19 Oct 2008, 03:50
my answer is B
(1) is ins
(2) is sufficient-
the only way the sum of the 2 sets is equal - for both sets, the mean and the average equal zero ==> symmetry around zero with an odd number of consequtive integers
example:
-2,-1,0,1,2
or -3,-2,-1,0,1,2,3
so (2) is sufficient
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Re: Two GMAT prep DS questions [#permalink]
19 Oct 2008, 04:03
Set S consists of 5 consecutive integers and set T consists of 7 consecutive integers. Is median of set S equal to the median of set T ?
1) Median of set S is 0 2) Sum of the numbers in S is equal to the sum of numbers in T
s = x,x+1, x+2, x+3, x+4 ( median is x+2) , t = y, y+1, y+2, y+3, y+4, y+5, y+6 ( median = y+3)
is x+2 = y+3 from one
x = -2.........insuff
from 2
5x+10 = 7y+21 ie: 5x-7y = 11 , 7y must end either in 9 as units digit or 4 thus y = 7 or y = 2
5x-14 = 11, ie: x = 5 or 5x-49 = 11 ie x = 12
in either cases x+2 is not = y+3..........suff
Haven't figured out the explanation for this yet..
'm' and 'r' are two numbers on the number line. What is the value of 'r' 1) The distance between r and 0 is three times the distance between m and 0 2) 12 is halfway between m and r.
from 1
/r/ = 3/m/........insuff
from 2
/m-12/ = /r-12/........insuff
both ..........E
I got this wrong but later figured out where i went wrong. Want to see if i can get a better and faster way to solve this one.
Thanks folks.[/quote]
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Re: Two GMAT prep DS questions
[#permalink]
19 Oct 2008, 04:03
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