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## 500 DS tricky

This topic has 2 member replies
dunkin77 Master | Next Rank: 500 Posts
Joined
01 Apr 2007
Posted:
269 messages

#### 500 DS tricky

Mon Apr 02, 2007 2:30 pm
Hi,

I thought the answer is E) but the correct answer is B).

i) says if there is 2, there should be -2 in S; however, ii) says a and b (differrent number) can be multiplied "ab" but it dose not say same number a and -a can be multiplied..... I am confused..

. S is a set of integers such that
i) if a is in S, then -a is in S, and
ii) if each of a and b is in S, then ab is in S.
Is -4 in S?
(1) 1 is in S.
(2) 2 is in S.

dunkin77 Master | Next Rank: 500 Posts
Joined
01 Apr 2007
Posted:
269 messages
Mon Apr 02, 2007 7:33 pm
Okie - a and -a is different number then!

ajith Legendary Member
Joined
21 Sep 2006
Posted:
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Test Date:
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Target GMAT Score:
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Mon Apr 02, 2007 5:39 pm
dunkin77 wrote:
Hi,
ii) says a and b (differrent number) can be multiplied "ab" but it dose not say same number a and -a can be multiplied..... I am confused..
who said a and -a are not different numbers ???
It is quite different.

If it were same, could you please lend as much as you can, and later on I will say lending and borrowing are the same.

_________________
Always borrow money from a pessimist, he doesn't expect to be paid back.

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