mrinal2100 wrote:|x+2|=|y+2| what is the value of x+y?
(1) xy<0
(2) x>2 y<2
if mod (X+2) = mod (Y+2)
then (x+2)^2 = (Y+2)^2
there fore x^2 + 4X + 4 = Y^2 + 4Y + 4
X^2 - Y^2 = 4 (Y-X)
(X+Y)(X-Y) = -4(X-Y)
so X + Y = -4 ...
So i coould solve these with out even looking at here statement 1 and 2
Is there any mistake in my solution
Hey,
U r right but u have left the problem unfinished.
U can remember one more thing
if |X|=|Y| it is equal to |X|=+/-(y)
So considering the given data |x+2|=+/-(y+2)
first lets consider x+2=+(y+2)
Which gives u x=y
second lets consider x+2=-(y+2)
which gives u x+y=-4.
U left the problem here.
from above u can understand that one possible value for x+y=-4, but we also have got x=y that mean for every value u take for x (which is equal to y) u get different value for x+y
Eg: if x=2 then y also is 2 and here x+y =4 and not -4.
So u cannot say directly from the given statement.
Now consider Statement 1
1.xy<0
for the above to satisfy one should be +ve and the other should be -ve
ie., x +ve, y -ve or x -ve, y +ve
so taking this from the above got values x=y will not satisfy so value of x+y=-4
Statement 1 is sufficient
Now consider statement 2
x>2,y>2
from given statement x+y=-4 can ruled out since x and y are +ve
Now x=y can have more than one value for x+y since we can have many values to satisfy x>2,y>2
Statement 2 Not sufficient.
Ans
A Statement 1 alone is sufficient
Last edited by
aplavakarthik on Sun Aug 28, 2011 8:03 am, edited 1 time in total.
