MGMAT Advanced DS Problem
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Source: Beat The GMAT — Data Sufficiency |
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killer1387
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1) for y>0rinoa wrote:This is from the book by Manhattan GMAT. This may be a really stupid question, but I'm not understanding why statement 1 is insufficient for this problem:
If yz =/ 0 (cannot equal 0), is 0<y<1?
1) y < 1/y
2) y = z^2
y^2<1=> -1<y<1
ie. 0<y<1
for y<0
y^2>1
=> y<-1 and y>1
hence y<-1
hence insufficient
as for y>0 answer to required question is YES
and for y<0 answer is NO.
HTH












