DS-13
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- Master | Next Rank: 500 Posts
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- Master | Next Rank: 500 Posts
- Posts: 158
- Joined: Mon Dec 03, 2007 8:32 am
- Thanked: 7 times
Yup it's C. It's a shame.
From (1) we know x > y , so both could be +ve or -ve or whatever.
From (2) we don't know that x > y (this is the mistake I commited).
However, we do know that both x and y CAN be either +ve or -ve and |x| > |y|.
Combining both, x > y from (1). And 2 is impossible if we take -ve values for x and y in (2). Hence both must be positive.
All the best for your exam tomorrow by the way. Do let us know, how the test went and whether you encountered any probability problems, tricky problems etc.
Thanks,
Calista.
From (1) we know x > y , so both could be +ve or -ve or whatever.
From (2) we don't know that x > y (this is the mistake I commited).
However, we do know that both x and y CAN be either +ve or -ve and |x| > |y|.
Combining both, x > y from (1). And 2 is impossible if we take -ve values for x and y in (2). Hence both must be positive.
All the best for your exam tomorrow by the way. Do let us know, how the test went and whether you encountered any probability problems, tricky problems etc.
Thanks,
Calista.