Search found 3 matches
Couldn't k be a fraction. If k = -1/2 than adding 1 will make 1/(k+1) > 0 even though 1/k < 0. Looks like you changed the direction of the inequality. I think it should read: 1/(k+1) > 0 k+1 should be positive. therefore, k+1 > 0 hence k>-1 Same issue with 1 as well. Otherwise I think your setup is ...
- by krumpy
Sun Sep 06, 2009 2:06 pm- Forum: Data Sufficiency
- Topic: gmatprep
- Replies: 2
- Views: 1445
Are you sure it's B? Wouldn't the square of the reciprocal of -1 be 1, which is greater than 1/100? I would think it would be A:
n<-1/10 => n^2<1/100
so the reciprocal is less than -10
- by krumpy
Sun Sep 06, 2009 1:42 pm- Forum: Data Sufficiency
- Topic: gmat prep
- Replies: 4
- Views: 1707
I would choose E. You need the prob of 5 times b/c that qualifies as at least four times as well as the prob that you get exactly 4 heads. That is going to be 0.6^4*0.4 (4heads x one tail). Need to multiply by 5 as there are five differet ways for this outcome to occur (HHHHT,HHHTH,HHTHH,HTHHH,THHHH...
- by krumpy
Sat Sep 05, 2009 7:39 am- Forum: Problem Solving
- Topic: Probability- tough one!
- Replies: 4
- Views: 1734