Search found 80 matches
Re: Probability that a # is formed
A 5 digit number is formed using the digits 0,1,2,3,4&5 at random but without repetition. The probability that the number so formed is divisible by 5 is: A. 1/5 B. 2/5 C. 4/5 D. 3/10 E. 9/25 Answer is (B) The total number of 5-digit integers is: 5*5! (The first digit cannot be zero) The number ...
- by billzhao
Thu Mar 05, 2009 7:15 am- Forum: Problem Solving
- Topic: Probability that a # is formed
- Replies: 6
- Views: 1572
Re: Square - probability
The probability that a square selected at random from a 8X8 chess board is of size 3X3 is: A) 8/51 B) 14/17 C) 13/17 D) 25/204 E) 3/17 My answer is (E). the number of square of size 1*1: 8*8=64 the number of square of size 2*2: 7*7=49 the number of square of size 3*3: 6*6=36 the number of square of...
- by billzhao
Thu Mar 05, 2009 7:01 am- Forum: Problem Solving
- Topic: Square - probability
- Replies: 4
- Views: 8951
Re: Dollars - probability
A bag contains 4 $5 notes, 7 $2 notes and 9 $1 notes. If the 3 notes are drawn at random from the bag, then find the odds against drawing the minimum possible amount A) 99:88 B) 7:88 C) 88:95 D) 88:7 E) 90:7 My answer is (C) Probability of drawing the minimum possible amount = C(3,9)/C(3,20)=7/95, ...
- by billzhao
Thu Mar 05, 2009 6:54 am- Forum: Problem Solving
- Topic: Dollars - probability
- Replies: 3
- Views: 1109
Is the OA wrong?
I am wondering why the third statement is wrong?
There must be 7 houses sold below the median price, isn't it?
- by billzhao
Tue Feb 24, 2009 5:38 pm- Forum: Problem Solving
- Topic: Is the OA wrong?
- Replies: 2
- Views: 1343
Re: divided by 33
What is the remainder when 1044 * 1047 * 1050 * 1053 is divided by 33? A. 3 B. 27 C. 30 D. 21 E. 18 To find the remainder, we need to first find what are the remainders when 1044, 1047, 1050 and 1053 are divided by 33 individually. 1044/33=31.......21 1047/33=31.......24 1050/33=31.......27 1053/33...
- by billzhao
Tue Feb 24, 2009 7:10 am- Forum: Problem Solving
- Topic: divided by 33
- Replies: 7
- Views: 5552
- by billzhao
Tue Feb 24, 2009 2:03 am- Forum: Problem Solving
- Topic: A tricky word problem
- Replies: 1
- Views: 1171
- by billzhao
Tue Feb 24, 2009 1:57 am- Forum: Problem Solving
- Topic: Work problem
- Replies: 1
- Views: 1142
We have: (40%*X+25%*Y)/(X+Y)=30%, after simplication, we have Y=2*X
So X/(X+Y)=1/3=33 1/3%
Answer is (B)
- by billzhao
Mon Feb 23, 2009 5:55 pm- Forum: Problem Solving
- Topic: Other Arithmetic problems from 11th edition
- Replies: 1
- Views: 983
Re: Integer & Multiples
990=11*10*9, so n should be at least 11relaxin99 wrote:If n is a positive integer and the product of all the integers from 1 to n, inclusive, is a multiple of 990, what is the least value of n?
10
11
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14
- by billzhao
Mon Feb 23, 2009 5:28 pm- Forum: Problem Solving
- Topic: Integer & Multiples
- Replies: 3
- Views: 1290
- by billzhao
Mon Feb 23, 2009 5:24 pm- Forum: Problem Solving
- Topic: Function & Variable
- Replies: 1
- Views: 1045
Answer is (D) The total number of arrangements is: P5=120 (1.) Both couples are sitting adjacent to each other: P3*P2*P2=3!*2*2=24 (2.)1 couple is sitting adjacent to each other: P4*P2=4!*2=48 (3.) The other couple is sitting adjacent to each other: P4*P2=48 (4.) At least one couple is sitting adjac...
- by billzhao
Mon Feb 23, 2009 7:34 am- Forum: Problem Solving
- Topic: Couples on Chairs
- Replies: 4
- Views: 1676
Please help with this general quesiton.
Is there a method to identify whether a certain number is prime number or not?
For example: 3217, 4999
Thanks!
- by billzhao
Sun Feb 22, 2009 5:58 pm- Forum: GMAT Math
- Topic: Please help with this general quesiton.
- Replies: 3
- Views: 1533
- by billzhao
Sat Feb 21, 2009 9:00 pm- Forum: Data Sufficiency
- Topic: A tricky problem
- Replies: 1
- Views: 1260
Folks, here is the next one... From a vessel containing pure water 8 gallons of water is taken out and replaced by pure milk. Again 8 gallons of the resultant mixture is taken out and was substituted by pure milk.If the vessel now contains water and milk in the ratio 9:40, find the capacity(in gall...
- by billzhao
Sat Feb 21, 2009 8:38 pm- Forum: Problem Solving
- Topic: Problem Solving for 780+ Aspirants.
- Replies: 209
- Views: 63722
- by billzhao
Sat Feb 21, 2009 7:55 pm- Forum: Data Sufficiency
- Topic: Remainder problem
- Replies: 2
- Views: 1407