From
MGMAT " The question asks about the sign of d.
(1) INSUFFICIENT: When two numbers sum to a negative value, we have two possibilities:
Possibility A: Both values are negative (e.g., e = -4 and d = -8)
Possibility B: One value is negative and the other is positive.(e.g., e = -15 and d = 3).
(2) INSUFFICIENT: When the difference of two numbers produces a negative value, we have three possibilities:
Possibility A: Both values are negative (e.g., e = -20 and d = -3)
Possibility B: One value is negative and the other is positive (e.g., e = -20 and d = 3).
Possibility C: Both values are positive (e.g., e = 20 and d = 30)
(1) AND (2) SUFFICIENT: When d is ADDED to e, the result (-12) is greater than when d is SUBTRACTED from e. This is only possible if d is a positive value. If d were a negative value than adding d to a number would produce a smaller value than subtracting d from that number (since a double negative produces a positive). You can test numbers to see that d must be positive and so we can definitively answer the question using both statements. "
Any types/ shortcuts for this question and/or positive/Negatives questions in general? I tend to spend way too much time on these questions.