Search found 7 matches
- by 721tjm
Thu Mar 03, 2011 4:35 pm- Forum: Data Sufficiency
- Topic: If n is a positive integer, is n^3 - n divisible by 4?
- Replies: 12
- Views: 3727
I think this one might just be 2^6 = 64... How many possible answers are there for the first question? 2 ...second question? 2 and so forth Multiply all the different scenarios together to equal 2*2*2*2*2*2 = 2^6 = 64 I think Night reader's on the right track but maybe double-counted a couple possib...
- by 721tjm
Mon Feb 07, 2011 5:18 pm- Forum: Problem Solving
- Topic: permutation
- Replies: 6
- Views: 1549
Additional Practice Exams
I recently purchased the MGMAT books. The guides and practice exams have been great so far. I wanted to see if it's possible to purchase additional practice tests from MGMAT, or, alternatively, if there's another provider that MGMAT would recommend for additional tests. Thanks a lot.
- by 721tjm
Wed Feb 02, 2011 10:41 pm- Forum: Ask a Manhattan Prep representative
- Topic: Additional Practice Exams
- Replies: 2
- Views: 1804
- by 721tjm
Wed Feb 02, 2011 7:49 pm- Forum: Problem Solving
- Topic: Probability--suzan
- Replies: 7
- Views: 2793
Usually I'm ok with these but this one threw me for a loop. Could anyone explain the mistake in my approach? Take the unrestricted combinations and subtract out the restricted combinations Unrestricted = 7! = 5040 possible combinations Restriction 1: She won't sit in the first seat. How many ways ca...
- by 721tjm
Wed Feb 02, 2011 4:30 pm- Forum: Problem Solving
- Topic: Probability--suzan
- Replies: 7
- Views: 2793
Apologies for making that jump without explaining it. Mechanically, drawing N coins at once is the same as drawing one coin, then another coin, and additional coins until you’ve drawn N coins. To frame the problem in terms we can better describe, we can consider the latter case so that we can refe...
- by 721tjm
Thu Jan 27, 2011 3:53 pm- Forum: Problem Solving
- Topic: Probability
- Replies: 5
- Views: 2854
What's the probability she doesn't draw out a quarter after X trials? X=1: (10+5)/21 = 15/21 chance she doesn't draw a quarter first X=2: (10+5-1)/(21-1)=14/20 chance she doesn't draw a quarter on the second try after not drawing one the first time (15/21)(14/20) = 210/420 = .5 chance she won't have...
- by 721tjm
Wed Jan 26, 2011 5:06 pm- Forum: Problem Solving
- Topic: Probability
- Replies: 5
- Views: 2854