sudhir3127 wrote:eccentric wrote:Is a=b?
1. a+b < 0
2. ab < 0
i got for E
statement 1
assume a = -5 and b = 2
a + b <0 , -5 +2 <0...... hence insufficent
statement 2
a= -5 and b = 2
ab<0 ; -10 <0..............hence insufficient
combining 1 and 2 also doesnt help..
hence E
hope that helps
PS: My 500th post
You only demonstrate that a statement is insufficient if you get BOTH a "yes" answer AND a "no" answer. You're only partway done!
(1) a + b < 0
We can certainly pick the numbers you chose: a = -5 and b = 2
Now we ask the original question: is -5 = 2? NO.
To show that (1) is insufficient, we also need to get a "yes" answer.
We can also pick a = -2 and b = -2, since -2 + (-2) < 0
Is -2 = -2? YES.
Now that we have both a yes and a no, we can say that (1) is insufficent.
(2) ab < 0
Well, if the product of two numbers is negative, one MUST be negative and one MUST be positive.
If our numbers have different signs, is a = b? Definitely NOT. Therefore, (2) is sufficient.
(2) is sufficient, (1) is not: choose (B).
Remember, for yes/no data sufficiency questions, a definite "yes" OR a definite "no" is sufficient.
