HMMT 二月 2008 · GEN1 赛 · 第 9 题
HMMT February 2008 — GEN1 Round — Problem 9
题目详情
英文原题
- [ 5 ] A Sudoku matrix is defined as a 9 × 9 array with entries from { 1 , 2 , . . . , 9 }
and with the constraint that each row, each column, and each of the nine 1
3 × 3 boxes that tile the array contains each digit from 1 to 9 exactly once.2
?
A Sudoku matrix is chosen at random (so that every Sudoku matrix hasequal probability of being chosen). We know two of squares in this matrix,
as shown. What is the probability that the square marked by ? containsthe digit 3? 1
解析
英文解析
- [ 5 ] A Sudoku matrix is defined as a 9 × 9 array with entries from { 1 , 2 , . . . , 9 }
and with the constraint that each row, each column, and each of the nine 1
3 × 3 boxes that tile the array contains each digit from 1 to 9 exactly once.2
?
A Sudoku matrix is chosen at random (so that every Sudoku matrix hasequal probability of being chosen). We know two of squares in this matrix,
as shown. What is the probability that the square marked by ? containsthe digit 3?
Answer: Same as Combinatorics Test problem 6.2
121