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What is the mean of four consecutive even integers a ,b ,c [#permalink]
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05 Jan 2010, 05:13
What is the mean of four consecutive even integers a ,b ,c ,d ? i) a+d=b+c ii) da=b+c... although it is given as B ,i have a query... do we take the four consecutive even integers a ,b ,c ,d to be written in ascending order... if not then the ans should be C..... if the int are in ascending order , shudn't it be mentioned?
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06 Jan 2010, 05:16



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07 Jan 2010, 12:24
chetan2u wrote: What is the mean of four consecutive even integers a ,b ,c ,d ? i) a+d=b+c ii) da=b+c... although it is given as B ,i have a query... do we take the four consecutive even integers a ,b ,c ,d to be written in ascending order... if not then the ans should be C..... if the int are in ascending order , shudn't it be mentioned? Dont really understand your question.....(in red) The question is asking for the mean... of a,b,c,d all even integers... this means... we need to find the value of (a+b+c+d)/4 which would be an even integer for sure. ST1: gives a+d = b+c... This gives mean as (a+d)/2 or (b+c)/2.... hence NOT SUFF... ST2: gives da = b+c > d = a+b+c Therefore mean = (a+b+c+d)/4 = (d+d)/4 = d/2 .... Hence SUFF.... and answer is B Why would the order be required??? Cheers! JT
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Re: gmat club test [#permalink]
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07 Jan 2010, 17:24
jeeteshsingh wrote: chetan2u wrote: What is the mean of four consecutive even integers a ,b ,c ,d ? i) a+d=b+c ii) da=b+c... although it is given as B ,i have a query... do we take the four consecutive even integers a ,b ,c ,d to be written in ascending order... if not then the ans should be C..... if the int are in ascending order , shudn't it be mentioned? Dont really understand your question.....(in red) The question is asking for the mean... of a,b,c,d all even integers... this means... we need to find the value of (a+b+c+d)/4 which would be an even integer for sure. ST1: gives a+d = b+c... This gives mean as (a+d)/2 or (b+c)/2.... hence NOT SUFF... ST2: gives da = b+c > d = a+b+c Therefore mean = (a+b+c+d)/4 = (d+d)/4 = d/2 .... Hence SUFF.... and answer is B Why would the order be required???Cheers! JT u are giving ans as B... first why i think order is reqd... if the seq is a,b,c,d... x,x+2,x+4,x+6....SII gives da=b+c.... means x+6x=x+4+x+2....x=0 so nos are 0,2,4,6 mean =3...... but the eq da=b+c can be satisfied if ascending order is a,b,d,c eg. 2,0,2,4... here da=2(2)=4=4+0=4... mean in this case is 1... so two diff ans not suff... SIn SII combined are suff..... i would like the moderators to clarify on the issue pl...
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Re: gmat club test [#permalink]
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08 Jan 2010, 11:32
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chetan2u wrote: jeeteshsingh wrote: chetan2u wrote: What is the mean of four consecutive even integers a ,b ,c ,d ? i) a+d=b+c ii) da=b+c... although it is given as B ,i have a query... do we take the four consecutive even integers a ,b ,c ,d to be written in ascending order... if not then the ans should be C..... if the int are in ascending order , shudn't it be mentioned? Dont really understand your question.....(in red) The question is asking for the mean... of a,b,c,d all even integers... this means... we need to find the value of (a+b+c+d)/4 which would be an even integer for sure. ST1: gives a+d = b+c... This gives mean as (a+d)/2 or (b+c)/2.... hence NOT SUFF... ST2: gives da = b+c > d = a+b+c Therefore mean = (a+b+c+d)/4 = (d+d)/4 = d/2 .... Hence SUFF.... and answer is B Why would the order be required???Cheers! JT u are giving ans as B... first why i think order is reqd... if the seq is a,b,c,d... x,x+2,x+4,x+6....SII gives da=b+c.... means x+6x=x+4+x+2....x=0 so nos are 0,2,4,6 mean =3...... but the eq da=b+c can be satisfied if ascending order is a,b,d,c eg. 2,0,2,4... here da=2(2)=4=4+0=4... mean in this case is 1... so two diff ans not suff... SIn SII combined are suff..... i would like the moderators to clarify on the issue pl... If the question says that a,b,c,d are 4 consecutive even integers... I don't think they would consider them to be as 8,2,6,4..... ! Anyway... lets wait for Bunuel or someone else to comment on this! For me... Ans as B looks pretty convincing!
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Re: gmat club test [#permalink]
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08 Jan 2010, 20:03
hi .. i also think it should be given in ascending order... want to confirm it so that not found wanting in future... i m not sure where but i had done a q somewhere ,where the ans took the possiblity of they not being in an order..
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Re: What is the mean of four consecutive even integers a ,b ,c [#permalink]
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07 Dec 2011, 13:03
Anyone want to try this one ?? Not sure. I think the answer should be E as we donot know the order of consecutive integers.
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Re: What is the mean of four consecutive even integers a ,b ,c [#permalink]
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08 Dec 2011, 12:25
chetan2u wrote: What is the mean of four consecutive even integers a ,b ,c ,d ? i) a+d=b+c ii) da=b+c... although it is given as B ,i have a query... do we take the four consecutive even integers a ,b ,c ,d to be written in ascending order... if not then the ans should be C..... if the int are in ascending order , shudn't it be mentioned? Statement 2: da=b+c therefore dc=a+b ; as we know c and d are consecutive even integers; dc=2 which gives us a+b=2 there is only one pair of consecutive a and b that works; 0 and 2. Therefore statement 2 is sufficient alone.



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Re: What is the mean of four consecutive even integers a ,b ,c [#permalink]
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22 Apr 2014, 09:28
AbhiJ wrote: Anyone want to try this one ?? Not sure. I think the answer should be E as we donot know the order of consecutive integers. I agree , plus we can use the following sequence: a<b<c<d 6<4<2<0 In this case; 60= 42 and mean will be 42/2= 3 while if we take the seq as 0<2<4<6 mean will be 4+2/2= 3 thus E



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Re: What is the mean of four consecutive even integers a ,b ,c [#permalink]
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22 Apr 2014, 09:57
chetan2u wrote: What is the mean of four consecutive even integers a ,b ,c ,d ? i) a+d=b+c ii) da=b+c... although it is given as B ,i have a query... do we take the four consecutive even integers a ,b ,c ,d to be written in ascending order... if not then the ans should be C..... if the int are in ascending order , shudn't it be mentioned? BELOW IS REVISED VERSION OF THIS QUESTION WITH A SOLUTION:What is the mean of four consecutive even integers \(a\), \(b\), \(c\) and \(d\), where \(a<b<c<d\)?(1) \(a + d = b + c\). That statement is true for ANY four consecutive even integers. Not sufficient. (2) \(b + c = d  a\). Let \(a=2k\), for some integer \(k\). Now, since \(a\), \(b\), \(c\) and \(d\) are consecutive even integers then \(b=2k+2\), \(c=2k+4\) and \(d=2k+6\). So, we have that \((2k+2)+(2k+4)=(2k+6)2k\) > \(k=0\) > \(a=0\), \(b=2\), \(c=4\) and \(d=6\) > \(mean=3\). Sufficient. Answer: B.
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Re: What is the mean of four consecutive even integers a ,b ,c
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