nitya34 wrote:OG had same prob except the "NE" part
C is perfect
shilpi84 wrote:Is |a| = b - c ?
(1) a + c NE(not equal) b
(2) a < 0
OA:C
if you change the statement 1 the answer is C.
Here is the logic.
First step rephrase the question
Is |a| = b - c ?
if you have absolute value you have to consider several cases
first what is inside the absolute value is positive. In our case a >0
second what is inside the absolute value is negative. In our case a < 0
third what is inside the absolute value is 0. In our case a = 0
rewriting the equations
a > 0 ---> a = b - c
a < 0 ----> a = c-b
a = 0 ----> b = c
now take a look at the statements
1)
a + c = b ---> a = b - c
is this sufficient to assure that |a| = b -c? no because a = b -c only if a < 0
not sufficient
2) a < 0 tells nothing about b and c. not sufficient
both together
a < 0 and a = b - c, this is just one of the equations of the rephrasing. so is sufficient