## Search found 659 matches

#### combination or permutation

###### Problem Solving

Thanks Pete.

So the takeaway would be to pay close attention to the context and look for those keywords that hint at distinction between cases?

by Gurpinder

Tue Nov 08, 2011 2:23 pm
Forum: Problem Solving
Topic: combination or permutation
Replies: 3
Views: 1073

#### distinguish comb/perm

##### distinguish comb/perm

Hi guys, having a little trouble distinguishing the two. Comb = unordered where order doesen't matter. perm = order matters. But, look at this questions: A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fi...

by Gurpinder

Tue Nov 08, 2011 2:08 pm
Forum: GMAT Math
Topic: distinguish comb/perm
Replies: 1
Views: 1389

#### combination or permutation

##### combination or permutation

I know that its ordered vs. unordered that decides which one it is; but is that the bottom line? can someone elaborate on what it means by ordered vs. unordered ? The principal of a high school needs to schedule observations of 6 teachers. she plans to visit one teacher each day for a work week (M-F...

by Gurpinder

Fri Nov 04, 2011 11:44 am
Forum: Problem Solving
Topic: combination or permutation
Replies: 3
Views: 1073

#### Work Problem

###### Problem Solving

Say, the work has 12 parts. Hence, X does one part in one hour. Hence, Y does 1/10 of one part in one hour. This is where I am confused. How can x do one part in one hour? X only does 2/3 of the job. So wouldn't you take the amount of work he "actually" did to calculate rate? Thats how I am getting...

by Gurpinder

Thu Oct 27, 2011 11:19 am
Forum: Problem Solving
Topic: Work Problem
Replies: 3
Views: 953

#### Work Problem

###### Problem Solving

Thanks Anurag.

I dont understand what I am doing wrong. Since we are plugging in a number for work, lets say work = 1.

----r-------t------d
x -- r -----12------2/3

12r=2/3
36r=2
r=1/18 <- rate of x

----r-------t------d
y -- 1/180 ---t------1/3

t/180=1/3
t=60

by Gurpinder

Thu Oct 27, 2011 10:53 am
Forum: Problem Solving
Topic: Work Problem
Replies: 3
Views: 953

#### Work Problem

##### Work Problem

Working independently x takes 12 hours to finish a certain work. He finishes 2/3 of the work. The rest of the work is finished by Y whose rate is 1/10 of X. In how much time does Y finish his work? I tried plugging in a smart number for work (12) which screws up the answer. Why is plugging in a num...

by Gurpinder

Thu Oct 27, 2011 9:37 am
Forum: Problem Solving
Topic: Work Problem
Replies: 3
Views: 953

#### verbal expression to algebraic expressions

###### GMAT Strategy

Hi Kavita, What a coincidence. My last message in this post was about a year back and then I took a break. Yesterday, I was doing word translations again and you messaged! Thanks for your advice. Currently, I am quite strong in number properties, equations, and FDP problems. However, I am still stru...

by Gurpinder

Fri Oct 21, 2011 8:37 am
Forum: GMAT Strategy
Topic: verbal expression to algebraic expressions
Replies: 7
Views: 2500

#### Redundant Info in an OG simple functions question?

##### Redundant Info in an OG simple functions question?

The question is quite simple. However, what is the point of stating the sequence {2,4,7} in the question? The reason I am asking this is because, I thought GMAT questions DO NOT provide useless information. And I got the right answer without even looking at the sequence numbers. Just curious. Maybe ...

by Gurpinder

Fri Oct 07, 2011 10:12 am
Forum: Problem Solving
Topic: Redundant Info in an OG simple functions question?
Replies: 2
Views: 546

#### multiplying by variables in inequalities

###### GMAT Strategy

Thanks Brian,

Always great hearing you!

by Gurpinder

Thu Oct 06, 2011 1:19 pm
Forum: GMAT Strategy
Topic: multiplying by variables in inequalities
Replies: 2
Views: 729

#### tough inequality

###### Data Sufficiency

thx.

i see what i was doing wrong. i need some coffee!

by Gurpinder

Thu Oct 06, 2011 12:25 pm
Forum: Data Sufficiency
Topic: tough inequality
Replies: 3
Views: 1015

#### tough inequality

##### tough inequality

if x is NOT = 0, is (x^2 +1)/x > Y? (1) x = y (2) y>0 I don't understand how (1) is not sufficient. To multiply by variable, we need to take the positive and the negative: (x^2 +1)/x > Y x^2 +1 > xy ? And stmt 1 says y=y hence the question becomes, x^2+1>x^2 ? In which case, YES! regardless of wheth...

by Gurpinder

Thu Oct 06, 2011 12:05 pm
Forum: Data Sufficiency
Topic: tough inequality
Replies: 3
Views: 1015

#### multiplying by variables in inequalities

##### multiplying by variables in inequalities

In the MGMAT book, it mentions that when multiplying by unknown variables, take both positive/negative scenarios into account

4/x<1/3?

1. 12<x

2. little confused here. do I take x to be -x?
4/-x<1/3
12<-x
-12>x?

?????

by Gurpinder

Thu Oct 06, 2011 10:32 am
Forum: GMAT Strategy
Topic: multiplying by variables in inequalities
Replies: 2
Views: 729

#### must you always check the validity of an absolute value?

##### must you always check the validity of an absolute value?

Do you always have to check whether the 2 solutions you got are valid?

by Gurpinder

Fri Sep 30, 2011 8:45 am
Forum: GMAT Math
Topic: must you always check the validity of an absolute value?
Replies: 3
Views: 1861

#### Absolute Value confusion

###### Data Sufficiency

ahhh

so when a question asks for a value it has to be a SINGLE NUMERICAL value. it can't be a variable OR multiple values.

correct?

by Gurpinder

Thu Sep 29, 2011 8:47 am
Forum: Data Sufficiency
Topic: Absolute Value confusion
Replies: 3
Views: 748