Search found 24 matches


80% choose course M and C.....

80% choose course M and course C....., how many people choose neither M nor C?

1. 50% choose M
2. 30% choose C but not M

How do we answer this question by drawing a draft? or is there any quicker way to do it?

by neilcao

Tue Feb 22, 2011 7:41 am
Forum: Data Sufficiency
Topic: 80% choose course M and C.....
Replies: 2
Views: 606

About remainder, Help

10/2^n find the remainder?
1. n is even number
2. n is multiples of 4

how do we deal with this kind of remainder questions, when something is like 10/2^n or maybe 12/4^n....

by neilcao

Tue Feb 22, 2011 7:10 am
Forum: Data Sufficiency
Topic: About remainder, Help
Replies: 6
Views: 880

Probability question

Two independent events, the probability of any of them to occur is P, what's the probability that one happens and the other not. (expressed in terms of p)

Could this be 2p(1-p)? Why is that?

by neilcao

Tue Feb 22, 2011 6:43 am
Forum: Problem Solving
Topic: Probability question
Replies: 1
Views: 630

Is H a prime number

Is H a prime number?

1. any factor of H is > H ^1/2
2. any factor of H is > H/2

by neilcao

Mon Feb 21, 2011 7:47 am
Forum: Data Sufficiency
Topic: Is H a prime number
Replies: 4
Views: 979

Bank interest rate questions

2% compound interest,no money put in and out in 10 years,the interests for two years is 5050, what's the original amount of money

by neilcao

Mon Feb 21, 2011 7:23 am
Forum: Problem Solving
Topic: Bank interest rate questions
Replies: 3
Views: 931

A number is the product of x numbers,

a number is the product of x numbers, when the number's last 6 digits are 0 (000000), what\s the least value of x?

we are talking about integers here.

by neilcao

Mon Feb 21, 2011 7:14 am
Forum: Problem Solving
Topic: A number is the product of x numbers,
Replies: 3
Views: 785

problem 80 drinks given to a group of people

80 bottles of drink are given to a group of people, the remaining number of drinks is 4 less than the number given to each person, which number cannot be the actual number of people in this group?


21 28 14 17 24

Suppose the total number of drinks is given evenly to each person

by neilcao

Mon Feb 21, 2011 6:55 am
Forum: Problem Solving
Topic: problem 80 drinks given to a group of people
Replies: 3
Views: 989

Last digit of (27145)* (10^11-10^10)/10^13

(27145)* (10^11-10^10)/10^13

what's the last digit of the result?

I assume the result is not a integer

by neilcao

Mon Feb 21, 2011 6:21 am
Forum: Problem Solving
Topic: Last digit of (27145)* (10^11-10^10)/10^13
Replies: 1
Views: 666
by neilcao

Mon Feb 21, 2011 5:07 am
Forum: Problem Solving
Topic: how do you solve this kind of questions between 100-999....
Replies: 3
Views: 11657

About remainder question

Maybe a poor example, some questions like this say: (7^243)+(7^22)-5 divided by 7, what is the remainder?

How to solve this kind of problem?


Thanks

by neilcao

Tue Feb 08, 2011 8:12 pm
Forum: Problem Solving
Topic: About remainder question
Replies: 3
Views: 1024

towerSpider wrote:this is ds forum. post it in ps.
Sorry already posted it again in PS: http://www.beatthegmat.com/sequence-pro ... tml#338264

by neilcao

Mon Feb 07, 2011 7:42 pm
Forum: Data Sufficiency
Topic: Sequence problem, a1, a2,..an
Replies: 2
Views: 715

Sequence problem, a1, a2,..an....

The sequence a1, a2,....an,.../ is such that an=4an-1 - 3,for all integers n>1. If ac=x, then a1=?

A. 4x-3
B. 16x-15
C. X+3/4
D. X+3/16
E. X+15/16


Is there any quick way to solve this problem?

Thanks

by neilcao

Mon Feb 07, 2011 7:40 pm
Forum: Problem Solving
Topic: Sequence problem, a1, a2,..an....
Replies: 1
Views: 1980

Sequence problem, a1, a2,..an

The sequence a1, a2,....an,.../ is such that an=4an-1 - 3,for all integers n>1. If ac=x, then a1=?

A. 4x-3
B. 16x-15
C. X+3/4
D. X+3/16
E. X+15/16


Is there any quick way to solve this problem?

Thanks

by neilcao

Mon Feb 07, 2011 8:39 am
Forum: Data Sufficiency
Topic: Sequence problem, a1, a2,..an
Replies: 2
Views: 715

Ten DS questions for discussion today

Q1.the tens digit of number N? D1. 10n hundreds digit is 2. D2. n-9 tens digit is 1. Q2. Someon is making a cake. Part of the cake is given to his company, and another part is given to his neighbor, he keeps the remaining part. Is the part he keeps 1/3 of the total? D1. The part he keeps is less tha...

by neilcao

Sat Jan 29, 2011 2:05 am
Forum: Data Sufficiency
Topic: Ten DS questions for discussion today
Replies: 1
Views: 624

Ten PS questions for discussion today

Q1.(4.32)*10^(-4) hundred thousandth? Q2. If S(N)=1+2+3...+N, find S(2N)-S(N)? Q3. Liquid A contains 25% of water,B 55%,when add A and B, the total volume is 300L,water is 35%, find B's volume? Q4. Out of 64 people,5 speaks German,6 speaks English,10 speaks Frence,everyone speaks a...

by neilcao

Sat Jan 29, 2011 1:33 am
Forum: GMAT Math
Topic: Ten PS questions for discussion today
Replies: 3
Views: 1051