AMC 8 1998 Problem 24
AMC8 1998 年第 24 题
余数与同余★★★★☆
A rectangular board of 8 columns has squares numbered beginning in the upper left corner and moving left to right so row one is numbered 1 through 8, row two is 9 through 16, and so on. A student shades square 1, then skips one square and shades square 3, skips two squares and shades square 6, skips 3 squares and shades square 10, and continues in this way until there is at least one shaded square in each column. What is the number of the shaded square that first achieves this result?
一块有 8 列的矩形板，方格从左上角开始从左到右编号，第一行为 1 到 8，第二行为 9 到 16，以此类推。一个学生涂黑了方格 1，然后跳过一个方格涂黑方格 3，跳过两个方格涂黑方格 6，跳过 3 个方格涂黑方格 10，并继续按此方式操作，直到每一列至少有一个涂黑的方格。首次达到此结果时涂黑的方格编号是多少？
- A.36
- B.64
- C.78
- D.91
- E.120
正确答案 · Correct Answer
E
解析 · Solution
解析整理中
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