Is a + b 0? (1) |a| |b| (2) a

Question

Is a + b > 0?

(1) |a| > |b|
(2) a < b

Self made - tricky

rahul16singh28 · Answer

From Stmnt 1 (a+b)(a-b)>0. So insufficient.
From Stmn 2 (a-b) < 0. Insufficient.

Combining 1 & 2...

a+b<0.

Please let me know if anything wrong with my approach.

pushpitkc · Answer

Is a + b > 0?

(1) |a| > |b|
Case 1: a=-7, b=-2 (a+b < 0)
Case 2: a=4, b=3 (a+b > 0) (Insufficient)

(2) a 0) (Insufficient)

Combining the information on both the statements, the expression
a+b can be negative only (Sufficient)(Option C)

amanvermagmat · Answer

(1) |a| > |b| means that the distance of 'a' from zero is greater than the distance of 'b' from zero, on the number line. But both could be positive (in which case a > b and a+b>0), both could be negative (in which case a b and a+b>0) or a negative, b positive (in which case a|b|, it could happen in two cases:
I) either both are negative but a is more away from zero than b
II) or a is negative, b is positive but distance of a from zero is more than distance of b from zero

In either of the two cases, sum will be negative. Or a+b<0. Sufficient.

Hence C answer

sananoor · Answer

Awesome question! seriously Chetan this is easy but tricky

Commendlionel · Answer

Really love this approach; can anyone confirm if this method is acceptable in the GMAT?

CEdward · Answer

Is a+b>0?

(1) |a|>|b|

a = 3, b =2 YES
a = -3, b = 2 NO

Insufficient

(2) a<b

Clearly insufficient.

Combo pack: 
a must have a greater absolute value relative to b, but still be less in (non-absolute) value. In other words, a + b is never > 0. 
Sufficient.

chetan2u · Answer

Number line (1) |a| > |b| The distance of a from 0 is more than the distance of b from from 0. Both a and b could be positive...Yes Both could be negative....No (2) a |b|^2...............a^2>b^2....a^2-b^2>0.......(a+b)(a-b)>0 Nothing more as a+b will depend on a-b. (2) a 0 , so a+b and a-b will have same sign. a-b<0, so a+b is also less than 0. Answer is NO C

Is a + b > 0? (1) |a| > |b| (2) a < b

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