And an explanation please
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
Data Sufficiency Question
This topic has expert replies
-
vikram4689
- Legendary Member
- Posts: 1325
- Joined: Sun Nov 01, 2009 6:24 am
- Thanked: 105 times
- Followed by:14 members
ans is C
i) x = -1 , n =1 , -3x is positive
ii) x = -1 , n =2 , -3x is negative
i) x = -1 , n =1 , -3x is positive
ii) x = -1 , n =2 , -3x is negative
Premise: If you like my post
Conclusion : Press the Thanks Button
Conclusion : Press the Thanks Button
-
Tani
- Legendary Member
- Posts: 1255
- Joined: Fri Nov 07, 2008 2:08 pm
- Location: St. Louis
- Thanked: 312 times
- Followed by:90 members
for -3x^n to be positive, x^n must be negative.
For that to be true, x must be negative and N must be a positive odd integer
We are told that x is negative and n is odd, however, we are not told that n is positive, so my answer would be E.
For that to be true, x must be negative and N must be a positive odd integer
We are told that x is negative and n is odd, however, we are not told that n is positive, so my answer would be E.
Tani Wolff
-
vikram4689
- Legendary Member
- Posts: 1325
- Joined: Sun Nov 01, 2009 6:24 am
- Thanked: 105 times
- Followed by:14 members
Hi Tani ,
I do not think it matters whether N is positive or negative. In case of negative N , fraction would be reciprocal of earlier fraction but positivity or negativity of x^n would remain intact.
x =-1 n =3 , x^n = (-1)^3 = -1
x =-1 n =-3 , x^n = (-1)^(-3) = 1/(-1)^3 = 1/-1= -1
I do not think it matters whether N is positive or negative. In case of negative N , fraction would be reciprocal of earlier fraction but positivity or negativity of x^n would remain intact.
x =-1 n =3 , x^n = (-1)^3 = -1
x =-1 n =-3 , x^n = (-1)^(-3) = 1/(-1)^3 = 1/-1= -1
Premise: If you like my post
Conclusion : Press the Thanks Button
Conclusion : Press the Thanks Button
