veritas prep question

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hmboy17: Master | Next Rank: 500 Posts; Posts: 141; Joined: Fri Mar 06, 2009 8:40 am

veritas prep question

by hmboy17 » Tue Sep 01, 2009 6:23 am

DS question-
is x+y > xy?
1) mode of x = y
2) x<0<y

Ans please?
I guess 2 is itself to answer this question
exp- if x= -2 y= 3
then x+y > xy ( 1 > -6)
but the OA is C. aNY ONE EXPLAIN.

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Source: Beat The GMAT — Data Sufficiency | Tue Sep 01, 2009 6:23 am

srivas: Senior | Next Rank: 100 Posts; Posts: 76; Joined: Fri Dec 26, 2008 8:18 am; Thanked: 3 times

by srivas » Tue Sep 01, 2009 7:32 am

statement II if we take values in fractions

x=-0.5, y = 0.3 x+y = -0.2 xy = -0.15 x+y < xy

x = -0.5, y = 2 x+y = 1.5 xy = -1 then x+y > xy

so insufficient

statement I mode of x = y
x= -0.5 and y = 0.5 x+y = 0 xy = -0.25 x+y > xy
x = -0.5 naad y = -0.5 x+y = -1 xy = 0.25 x+y <xy
insufficient

how it is C

Gmat710,, Hyd

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PussInBoots: Master | Next Rank: 500 Posts; Posts: 157; Joined: Tue Oct 07, 2008 5:47 am; Thanked: 3 times

by PussInBoots » Tue Sep 01, 2009 10:38 am

If I get it correct, mode of x is x itself. Problem does not make sense

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Stuart@KaplanGMAT: GMAT Instructor; Posts: 3225; Joined: Tue Jan 08, 2008 2:40 pm; Location: Toronto; Thanked: 1710 times; Followed by:614 members; GMAT Score:800

Re: veritas prep question

by Stuart@KaplanGMAT » Tue Sep 01, 2009 11:12 am

hmboy17 wrote:DS question-
is x+y > xy?
1) mode of x = y
2) x<0<y

Ans please?
I guess 2 is itself to answer this question
exp- if x= -2 y= 3
then x+y > xy ( 1 > -6)
but the OA is C. aNY ONE EXPLAIN.

You can only have the mode of a set. There's no such thing as "the mode of a number".

Even if we could take the mode of a number (which I maintain that we can't and is a nonsensical idea), it would have to be the number itself; however, statement (2) clearly states that x does NOT equal y.