Nepal National Olympiad
Source: Nepal Mathematics Olympiad
April 22, 2018
combinatorics
Problem Statement
Problem Section #4c) A special deck of cards contains cards, each labeled with a number from to and colored with
one of seven colors. Each number-color combination appears on exactly one card. John will select
a set of eight cards from the deck at random. Given that he gets at least one card of each color and
at least one card with each number, the probability that John can discard one of his cards and still
have at least one card of each color and at least one card with each number is , where and are
relatively prime positive integers. Find .