IS a.b positive?
1) (a+b)^2 < (a-b)^2
2) a=b
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
Numbers DS
This topic has expert replies
-
shankar.ashwin
- Legendary Member
- Posts: 966
- Joined: Sat Jan 02, 2010 8:06 am
- Thanked: 230 times
- Followed by:21 members
-
knight247
- Legendary Member
- Posts: 504
- Joined: Tue Apr 19, 2011 1:40 pm
- Thanked: 114 times
- Followed by:11 members
1) (a+b)² < (a-b)²
Just expand the brackets
a²+2ab+b²<a²-2ab+b²
4ab<0
ab<0 SUFFICIENT
2)a=b both have the same magnitude and sign. So whether both are negative or both are positive a*b>0
SUFFICIENT
D
Just expand the brackets
a²+2ab+b²<a²-2ab+b²
4ab<0
ab<0 SUFFICIENT
2)a=b both have the same magnitude and sign. So whether both are negative or both are positive a*b>0
SUFFICIENT
D
-
shankar.ashwin
- Legendary Member
- Posts: 966
- Joined: Sat Jan 02, 2010 8:06 am
- Thanked: 230 times
- Followed by:21 members
Me did the same..
OA is A, possibility that a=b=0 in 2nd statement.
Really get pissed doing these mistakes time and again.
OA is A, possibility that a=b=0 in 2nd statement.
Really get pissed doing these mistakes time and again.
knight247 wrote:1) (a+b)² < (a-b)²
Just expand the brackets
a²+2ab+b²<a²-2ab+b²
4ab<0
ab<0 SUFFICIENT
2)a=b both have the same magnitude and sign. So whether both are negative or both are positive a*b>0
SUFFICIENT
D
