Is ab odd?
1. a is even
2. a is an integer
Odd even
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Hi sud21,
This question can be solved by TESTing VALUES.
We're asked if (A)(B) is odd. This is a YES/NO question.
1) A is EVEN
IF....
A = 2
B = 1
(A)(B) = 2 and the answer to the question is NO.
IF....
A = 2
B = 1/2
(A)(B) = 1 and the answer to the question is YES.
Fact 1 is INSUFFICIENT
2) A is an INTEGER
The same two TESTS that we used in Fact 1 can be used here:
IF....
A = 2
B = 1
(A)(B) = 2 and the answer to the question is NO.
IF....
A = 2
B = 1/2
(A)(B) = 1 and the answer to the question is YES.
Fact 2 is INSUFFICIENT
Combined, we already have two different results that fit BOTH Facts.
Combined, INSUFFICIENT
Final Answer: E
GMAT assassins aren't born, they're made,
Rich
This question can be solved by TESTing VALUES.
We're asked if (A)(B) is odd. This is a YES/NO question.
1) A is EVEN
IF....
A = 2
B = 1
(A)(B) = 2 and the answer to the question is NO.
IF....
A = 2
B = 1/2
(A)(B) = 1 and the answer to the question is YES.
Fact 1 is INSUFFICIENT
2) A is an INTEGER
The same two TESTS that we used in Fact 1 can be used here:
IF....
A = 2
B = 1
(A)(B) = 2 and the answer to the question is NO.
IF....
A = 2
B = 1/2
(A)(B) = 1 and the answer to the question is YES.
Fact 2 is INSUFFICIENT
Combined, we already have two different results that fit BOTH Facts.
Combined, INSUFFICIENT
Final Answer: E
GMAT assassins aren't born, they're made,
Rich
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S1::
If a = 2 and b = 3, no
If a = 2 and b = (1/2), yes
NOT SUFFICIENT
S2::
We don't know anything about a and b's values.
S1 + S2::
We STILL don't know about b! So we can't solve, unfortunately.
If a = 2 and b = 3, no
If a = 2 and b = (1/2), yes
NOT SUFFICIENT
S2::
We don't know anything about a and b's values.
S1 + S2::
We STILL don't know about b! So we can't solve, unfortunately.
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Notice that statement 2 does not add ANY EXTRA information beyond the information that statement 1 provides.sud21 wrote:Is ab odd?
1. a is even
2. a is an integer
So, if statement 1 is insufficient, then statement 2 must also be insufficient, and the COMBINED statements are insufficient.
Cheers,
Brent
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Now that is an excellent point, and one that will apply to lots of other DS questions too.Brent@GMATPrepNow wrote:Notice that statement 2 does not add ANY EXTRA information beyond the information that statement 1 provides.sud21 wrote:Is ab odd?
1. a is even
2. a is an integer
So, if statement 1 is insufficient, then statement 2 must also be insufficient, and the COMBINED statements are insufficient.
Cheers,
Brent