Data Sufficiency

Is |x| + |x-1| = 1 ?
1) x >= 0
2) x <= 1

OA C

we can frame the question as: Is sum of 2 +ve numbers equal to 1?

from 1:
x>=0
If x=0, |x| + |x-1| = 1
If x=3, |x| + |x-1| not equal 1
NOT SUFFICIENT

from 2:
x <= 1
If x=0, |x| + |x-1| = 1
If x=-3, |x| + |x-1| not equal 1
NOT SUFFICIENT

combining 1 and 2:
0<=x<=1
SUFFICIENT
Since the 2 parts of LHS are x and positive difference between x and 1, the sum will always be 1
RHS:
if first term is 0, second term is 1
if first term is 0.3, second term is 0.7 etc etc

answer C

jainrahul1985 wrote:Is |x| + |x-1| = 1 ?
1) x >= 0
2) x <= 1
OA C

given that |x| + |x-1| = 1
is it not implied that 0<=x<=1
isn't
1) x >= 0
2) x <= 1
obvious ?