Search found 54 matches
Primes
If A is a prime number, what is the value of A?
1) 0 < A < 10.
2) (A – 2) is divisible by 3.
OA is E
Why not C? if both statements combined together, then A must equal 5 for A-2 to be divisible by 3. Does GMAT expect also 0 to be divisible by 3???? (2-2 = 0, 0/3)???
Thanks!!
- by oks
Sat Aug 08, 2009 4:47 pm- Forum: Data Sufficiency
- Topic: Primes
- Replies: 3
- Views: 1438
Probability - coin toss
What is the probability of getting an identical result on three consecutive tosses of a coin?
a. 1/2
b. 1/4
c. 1/8
d. 1/16
e. 1/2 + 1/4
OA is B. Why not C?
The way I solved it: 3C3/2^3 = 1/8
- by oks
Sat Aug 08, 2009 4:43 pm- Forum: Problem Solving
- Topic: Probability - coin toss
- Replies: 2
- Views: 1541
Speed problem
12. A snail, climbing a 20 feet high wall, climbs up 4 feet on the first day but slides down 2 feet on the second. It climbs 4 feet on the third day and slides down again 2 feet on the fourth day. If this pattern continues, how many days will it take the snail to reach the top of the wall? (a) 12 (b...
- by oks
Sat Aug 08, 2009 3:54 pm- Forum: Problem Solving
- Topic: Speed problem
- Replies: 2
- Views: 1344
Consecutive points
5. A, B, C and D are four consecutive points on a straight line. What is the distance between A to D?
(1) AC = 6.
(2) BD = 8.
OA is E. I am not sure why not D? Would not consecutive points mean equally spaced?
Thanks!
- by oks
Sat Aug 08, 2009 3:47 pm- Forum: Data Sufficiency
- Topic: Consecutive points
- Replies: 1
- Views: 3273
PS - combinations
A certain restaurant offers 6 kinds of cheese and 2 kinds of fruit for its dessert platter. If each dessert platter contains an equal number of kinds of cheese and kinds of fruit, how many different dessert platters could the restaurant offer? A. 8 B. 12 C. 15 D. 21 E. 27 OA is E. My approach - 8!/6...
- by oks
Sun Jul 05, 2009 2:57 pm- Forum: Problem Solving
- Topic: PS - combinations
- Replies: 1
- Views: 1436
DS - absolute values
Is ¦x - y¦>¦x - z¦?
(1) ¦y¦>¦z¦
(2) x < 0
OA is E.
I must be missing something while solving this type of problem (absolute values). Could someone please explain the correct approach? Thanks!!
- by oks
Sun Jul 05, 2009 2:29 pm- Forum: Data Sufficiency
- Topic: DS - absolute values
- Replies: 1
- Views: 1138
DS - number of students
If each of the students in a certain mathematics class is either a junior or a senior, how many students are in the class? (1) If one student is to be chosen at random from the class to attend a conference, the probability that the student chosen will be a senior is 4/7. (2) There are 5 more seniors...
- by oks
Sun Jul 05, 2009 1:46 pm- Forum: Data Sufficiency
- Topic: DS - number of students
- Replies: 1
- Views: 1118
- by oks
Tue Jun 23, 2009 9:38 am- Forum: Sentence Correction
- Topic: Although it claims to delve into political issues
- Replies: 12
- Views: 8955
- by oks
Mon Jun 15, 2009 7:18 pm- Forum: Data Sufficiency
- Topic: Inequalities
- Replies: 5
- Views: 1588
Lines and coordinates
4. On the number line, if x is halfway between -5 and 3, and if y is halfway between -2 and 6, what number is halfway between x and y ?
(A) -1
(B) - 1/2
(C) 0
(D) 1/2
(E) 1
OA is D. Thanks!
- by oks
Sun Jun 14, 2009 2:07 pm- Forum: Problem Solving
- Topic: Lines and coordinates
- Replies: 1
- Views: 1166
I got this from the Plus series tests. My answer was also A - which is 90. I guess it's an error in the Plus test answers.
- by oks
Sat Jun 13, 2009 9:38 am- Forum: Problem Solving
- Topic: quick method to solve this
- Replies: 6
- Views: 1534
tohellandback, how do you know when to use the combinations and when - permutations formula? since this particular problem doesn't say anything about the order/arrangements (hence, permutations)...
- by oks
Sat Jun 13, 2009 9:29 am- Forum: Problem Solving
- Topic: Combinations problem
- Replies: 6
- Views: 1392
tohellandback, why is minimum 10?? i'm not sure i follow...
i get the maximum part. it is the minimum what i struggle with.
thanks!!!
- by oks
Sat Jun 13, 2009 9:26 am- Forum: Problem Solving
- Topic: Unions problem
- Replies: 13
- Views: 1732
- by oks
Sat Jun 13, 2009 9:18 am- Forum: Problem Solving
- Topic: Unions problem
- Replies: 13
- Views: 1732
Combinations problem
There are four contestants in the competition for 6 different prizes. Each contestant can win one prize. How many different outcomes are possible at the competition for the four contestants? A) 15 B) 30 C) 60 D) 180 E) 360 OA is E. Should not it be A?? The problem is 6C4 = 6!/4!2! = 5*6/2 = 15 The a...
- by oks
Fri Jun 12, 2009 5:28 pm- Forum: Problem Solving
- Topic: Combinations problem
- Replies: 6
- Views: 1392