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Goodlife
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 Posted: Fri Aug 15, 2008 9:12 pm Post subject: Help me, plz.. |
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I tried to search thses question, but I can't.
What is the answer of these question?
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If x + y is an integer, is y an integer?
(1) x – y is an integer.
(2) x + 2y is an integer.
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Is x < y ?
(1) The ratio of x to y is 7/9.
(2) xy > 0
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parallel_chase
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| Posted: Sat Aug 16, 2008 1:33 am Post subject: |
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Ques 1
I think answer is B
x+y is integer is y an integer
Statement I
x-y is integer, this same as saying x+y is integer.
Insufficient.
Statement II
x+2y is integer, if x+y is integer & x+2y is integer, y and x both have to be integers.
Ques 2
I think the answer is E
Statement I
x and y are in ratio 7:9
for 63 x<y
for -63 x>y
Therefore insufficient.
Statement II
xy>0
x and y both are positive
or
x and y both are negative
Therefore, insufficient.
Combining I & II
xy>0
x/y=7/9
still have both the cases positive or negative.
Hence insufficient.
Whats are the OAs? |
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classic
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| Posted: Sat Aug 16, 2008 8:50 am Post subject: |
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Q 1
WHAT IF X=1 AND Y=0.5
THEN X+ 2Y= 1 +2*.5=2 AND INTEGER
Also X= 0.8 and Y=0.1
So B is also InSuff...
Opt 1.
X-Y will only be integer when x=y ( incase anyone or both x or y is non integer)
Wld go for C ( Both options are reqd.. to solve this problem) |
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sudhir3127
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| Posted: Sat Aug 16, 2008 10:36 am Post subject: |
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| classic wrote: | Q 1
WHAT IF X=1 AND Y=0.5
THEN X+ 2Y= 1 +2*.5=2 AND INTEGER
Also X= 0.8 and Y=0.1
So B is also InSuff...
Opt 1.
X-Y will only be integer when x=y ( incase anyone or both x or y is non integer)
Wld go for C ( Both options are reqd.. to solve this problem) |
"WHAT IF X=1 AND Y=0.5" this cannot happen because the question says X+Y is an integer and 1+0.5 is not an integer... so u cant that assumption..
hope its clear.. |
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Goodlife
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| Posted: Sat Aug 16, 2008 10:38 am Post subject: Answers are.. |
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1. B
2. E
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Thx for answer, from them, I understand Q1,
but Q2's condition 1).. I can't still get it.
Because
x : y = 7 : 9 <-- This mean that y is bigger than x, right?
so, I think the answer is A, not E.
But officially the answer is E.
This is my problem. |
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sudhir3127
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| Posted: Sat Aug 16, 2008 10:45 am Post subject: Re: Answers are.. |
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| Goodlife wrote: | 1. B
2. E
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Thx for answer, from them, I understand Q1,
but Q2's condition 1).. I can't still get it.
Because
x : y = 7 : 9 <-- This mean that y is bigger than x, right?
so, I think the answer is A, not E.
But officially the answer is E.
This is my problem. |
I will try to explain u the 2nd question.
Is x < y ?
(1) The ratio of x to y is 7/9.
(2) xy > 0
if u take the first case... asssume that X is 49 and Y is 63
then the ratio is 7:9 and X<Y but what if X is -49 and Y is -63 .. even in that case the ratio is 7:9 but here X>Y.
so statement 1 is insufficient..
Statement 2 .. use the same number..
X=49, Y=63 XY>0 and X>Y
but if X=-49 and Y =-63 still XY>0 but X<Y
hence in sufficient .. Even with both ur not sure abt the signs of the numbers
Therefore the answer is E.
hope it helps.. do let me know if u have any doubts.. |
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