gmat Prep
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Source: Beat The GMAT — Data Sufficiency |
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way2kailash
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As X is a factor of Y and Y factor of Z, x is a factor of Z
Both statements are by themselves sufficient :
A) XZ is even.
For XZ to be even, X-odd Z- even, X- even Z - odd, X- even Z- even.
As X is a factor of Z, X-even and Z- odd is not possible as anything multiplied by even is even. So in remaining both cases Z is even.
B) Y is even.
As Y is factor of Z and Y is even, Z has to be even, again by same logic that even * (even or odd) = even
Both statements are by themselves sufficient :
A) XZ is even.
For XZ to be even, X-odd Z- even, X- even Z - odd, X- even Z- even.
As X is a factor of Z, X-even and Z- odd is not possible as anything multiplied by even is even. So in remaining both cases Z is even.
B) Y is even.
As Y is factor of Z and Y is even, Z has to be even, again by same logic that even * (even or odd) = even
