gmat009 wrote:OA is C but IMO B is sufficient.
From B I am getting r+s=0
r=-s, so B is sufficient.
Why answer is C. Can someone plz. explain why do we need A

Gmat009,

Lets do this exercise:

Solve this question for

S=0

and

S<0

let's see what you get. Feel free to use numbers.

logitech wrote:

gmat009 wrote:OA is C but IMO B is sufficient.
From B I am getting r+s=0
r=-s, so B is sufficient.
Why answer is C. Can someone plz. explain why do we need A

Gmat009,

Lets do this exercise:

Solve this question for

S=0

and

S<0

let's see what you get. Feel free to use numbers.

We cannot take s=0.
In option B he says that "Distance between t and -s".
If s is 0 the 2nd equation cannot say -s becoz 0 is neither positive nor negative.
Let me know if I am thinking wrong or missing something

gmat009 wrote:
Let me know if I am thinking wrong or missing something

You are good. Try the next one:

S<0

logitech wrote:

gmat009 wrote:
Let me know if I am thinking wrong or missing something

You are good. Try the next one:

S<0

If s<0 , then r=-(-s)
r=s and s=-s
Therefore this is sufficient becoz if s=-3, then r=3, if s=-4, then r=4
So r and s have opposite signs and 0 is halfway between r and s

Now take s>0
This is also sufficient becoz if s=3, then r=-3, if s=4, then r=-4
So r and s have opposite signs and 0 is halfway between r and s

Regardless s is positive or negative, r is opposite to s and 0 lies in midway

gmat009 wrote:

logitech wrote:

gmat009 wrote:
Let me know if I am thinking wrong or missing something

You are good. Try the next one:

S<0

If s<0 , then r=-(-s)
r=s and s=-s
Therefore this is sufficient becoz if s=-3, then r=3, if s=-4, then r=4
So r and s have opposite signs and 0 is halfway between r and s

Now take s>0
This is also sufficient becoz if s=3, then r=-3, if s=4, then r=-4
So r and s have opposite signs and 0 is halfway between r and s

Regardless s is positive or negative, r is opposite to s and 0 lies in midway

R----------S---------T-------------O---------------- -S

-S.................0-------R--------S----------T


-S------R----0----------S------------T

R----------S---------0---------------t--------S

R----------S---------0---------S-------t-

Think again:

TR is equal to T-S ?