we have to prove u^2+v^2=r^2+s^2 stmt 1 - not suff stmt2 u=1-r squaring both sides....u^2=1-2r+r^2 ....eqn1 v=1-s squaring both sides....v^2=1-2s+s^2.....eqn2 adding eqn1 and eqn2 u^2 + v^2=2-2r-2s+r^2 +s^2 ..not suff combining 1 and 2 u^2 + v^2=2-2r-2s+r^2 +s^2 u^2 + v^2=2-2(r+s)+r^2 +s^2 substitut...

Even my exam is tomorrow.....
Good luck..

oops..under wrong forum section..mods,can you please move this question to DS section..Thanks...

Ian, Why can't we trace back in reverse direction for stmt2 just like u did for stmt1...say 150 is in K..149 should also be in K as 150 = 149+1..hence B is also sufficient? That would be the trap in the question. Note the question only says that "if the integer r is in K, then r+1 is also in K...

@Q1 from Q: x^2+bx+c=(x+d)^2 x^2+bx+c=x^2+2dx+d^2 b=2d c=d^2 from 1, d=3..c=d^2 hence c=9..sufficient.. from 2 b=6 b=2d...d=b/2= 6/2=3...sufficient.. Hence 'D'..what do u guys think?? Please correct me if I am making an mistake... what is the OA? guye...any comment on my approach?? I am not sure wh...

@Q1
from Q:
x^2+bx+c=(x+d)^2
x^2+bx+c=x^2+2dx+d^2
b=2d
c=d^2

from 1,
d=3..c=d^2 hence c=9..sufficient..

from 2
b=6
b=2d...d=b/2= 6/2=3...sufficient..

Hence 'D'..what do u guys think?? Please correct me if I am making an mistake...
what is the OA?

bha, I tam sorry if my way does not satisfy you! If I look at the problem some seconds and I have a method which can enable me to solve it in less than 2 minutes I do it. Unfortunately, we cannot always have a better choice than what we think during the first seconds. But if you can have the right ...

gmat prep - DS

Help please....