If you have problems with combination and probability you can use this reference page to find information quickly. I guess my small contribution to the GMATclub community will help other people to crack 800 score.
#1. Com-prob problems always have a few different solutions. Try to solve the problems in many ways, and that will give you self-reliance.
#2. Use enumeration of possibilities for the problems with complex restrictions.
#3. "How can I apply here C^n_k or P^n_k?" - is a wrong question. Always understand what the formulas mean.
LINKS
easy - 56860 - 6 boys and 4 girls easy - 56779 - 10 red, 5 blue, 12 yellow pills. easy - 56728 - 10 marbles contains 3 red marbles and 7 blue marbles easy - 56446 - 4 people and integers between 1 and 4 easy - 56419 - an iced tea easy - 55984 - a contest consists of n questions easy - 55939 - 15 chess players easy - 55734 - 3 candidates for a university easy - 55689 - a pack of candy (2) easy - 55644 - a five-question true/false section easy - 55515 - a pack of candy easy - 54481 - red and blue chips medium - 58914 - a junior class has 1,000 students and a senior class has 800 students medium - 58887 - that include Michael also include Anthony medium - 58742 - 2 couples and 1person are seated in a row medium - 58675 - n(n + 1)(n + 2) is divisible by 8 medium - 58670 - Probability of Winning medium - 58640 - 4 people out of the 12 meried couples medium - 58629 - two ineger sets medium - 58609 - 9 people in the room medium - 58529 - 2 objects collide on a cube medium - 58521 - DS: heads than tails medium - 58476 - Marco and Maria toss a coin three times medium - 58360 - two ineger sets (2) medium - 58357 - coin is flipped 5 times medium - 58352 - 11 women and 9 men in a certain club medium - 58350 - DS: 10 light bulbs medium - 58233 - SQUARE medium - 58187 - A certain company assigns employees to offices medium - 58160 - 3 people are to be selected out of 8 people medium - 58095 - Bob are among the 5 participants in a cycling race medium - 58016 - 3 people is to be selected from 5 married couples medium - 57997 - junior class has 1000 students and senior class has 800 students medium - 57981 - positions at univeristy medium - 57980 - women and men of 10 employees medium - 57957 - rain on any given day in City X medium - 57916 - a and b from a set of 4 consecutive integers medium - 57882 - Anthony and Michael sit on the six-member board of directors for company X medium - 57799 - A fair die is rolled once and a fair coin is flipped once medium - 57695 - 3 dwarves and 3 Elves medium - 57645 - A contest will consist of n questions medium - 57629 - coin medium - 57615 - A jar contains b black, w white, and r red marbles medium - 57601 - GMPJBC medium - 57577 - 5 people are to be seated around a circular table medium - 57554 - Coach Miller medium - 57332 - A coach will make 3 substitutions medium - 56826 - 7 people and friendship medium - 56814 - coin with sides marked heads and tails medium - 56814 - tails side up more than five times medium - 56812 - a election in Burghtown. medium - 56709 - A set consist of 2n-1 element medium - 56705 - 25 lines medium - 56681 - 2 numbers from 1,2,3,4,5 medium - 56590 - 2 red and 3 blue marbles medium - 56586 - different colors from 6 flowers. medium - 56585 - 4 particular flowers of 8 different flowers medium - 56572 - five-digit numbers medium - 56557 - a committee of 4 distinct pairs of brothers and sisters medium - 56556 - three letters taken from letters (a,a,b,b,c,c,d) medium - 56530 - 12 playing cards medium - 56530 - 4 cards of 12 cards medium - 56446 - 4 people choose an integer between 1 and 4, inclusive. medium - 56445 - 5 of 7 models medium - 56443 - Two couples and one single person in a row of five chairs. medium - 56349 - 3 girls and 4 boys in a row medium - 56327 - shirts, shoes, pants medium - 56122 - Six mobsters: Frankie behind Joey medium - 56037 - a team from men and women medium - 55870 - 3 cars medium - 55823 - 4 senior partners and 6 junior partners medium - 55811 - 5 women are in a race medium - 55803 - a committee from 4 married couples medium - 55764 - 100 numbered cubes medium - 55743 - A and B stocks medium - 55694 - Two fair dices medium - 55673 - 3 different marbles medium - 55644 - GMATT answers medium - 55617 - 4 guys, 2 girls and 14 dogs. medium - 55509 - A committee of 3 people from 4 couples medium - 55504 - Ways from A to D medium - 55472 - 4 pairs of brothers and sisters medium - 55427 - 4 books fom 2 paperback and 6 hardback books medium - 55421 - the probability that n(n+1)(n+2) will be divisible by 8 medium - 55413 - 3-digit integer medium - 55410 - A committee from 5 military officers and 9 civilians. medium - 55383 - 4 physics, 2 math and 3 chemistry books medium - 55372 - My name is AJEET medium - 55369 - 8 friends want to play doubles tennis medium - 55366 - The most expensive two books medium - 55340 - trhee letters from seven different postboxes medium - 55311 - 6 cards medium - 55253 - Rich has 3 green, 2 red and 3 blue balls in a bag medium - 55141 - A bowl contains white and black balls. medium - 55071 - 10 bottles of alcohol medium - 55054 - 3 sniper's shoots medium - 54794 - a fantasy football game medium - 54650 - 6 cards medium - 54332 - Bob and Jen in a race medium - 53774 - The choir consists of 5 boys and 6 girls medium - 50488 - 5 digit numbers medium - 45753 - a committe of 3 of 6 people medium - 41464 - deck contains 2 blue, 2 red, 2 yellow, and 2 green cards medium - 19685 - 5 digit numbers formed using the digits 0, 1, 2, 3, 4, 5 medium - 15366 - Mary and Joe throw three dice each medium - 59065 - A 4-letter code hard - 58616 - PS Standard deviation + probabilities hard - 57713 - the total number of permutations of n different things hard - 57447 - A fair coin is tossed 10 times hard - 57169 - DS: How many subordinates does Marcia Have
7-t-44300.html - good collection of Math links. \tohttp://gmatclub.com/forum/7-t-56486.html - Combination-Permutation-Probability quant problems: my list with links 7-t-57156.html - Combination-Permutation-Probability quant problems: list of 55 different question with explanation [Amardeep Sharma]
Medium - 79490 - How many four-digit odd numbers do not use any digit more than once Meidum - 79312 - A jar contains only x black balls and y white balls
Last edited by bb on Tue Jun 09, 2009 5:12 pm, edited 4 times in total.
Added questions
buffdaddy
Re: COMBINATION and PROBABILITY - references. [#permalink]
Posted: Mon Jan 21, 2008 11:33 pm
Director
Joined: Sun Oct 14, 2007 Posts: 798 Location: Oxford Schools: Oxford'10 Followers: 8
Walker - awesome; simply awesome. Are you Walker as in Walker: Texas Ranger. Because if you are, a Chuck Norris reference comes to mind: "When Chuck Norris falls into water, he does not get wet. The water gets Chuck Norris."
Nice one man.
x2suresh
Re: COMBINATION and PROBABILITY - references. [#permalink]
Posted: Thu Jun 04, 2009 9:32 am
SVP
Joined: Wed Nov 07, 2007 Posts: 2198 Location: New York Followers: 13