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

How can E be correct if each broadcasts, not broadcast??

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

Inequalities

Is 2 < x < 4?
1) x² - 5x + 6 < 0
2) 5x² - 25x > 0

OA is D.

Thanks.

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