AMC 8 1995 Problem 23
AMC8 1995 年第 23 题
基本计数原理★★★★☆
Problem How many four-digit whole numbers are there such that the leftmost digit is odd, the second digit is even, and all four digits are different?
有多少个四位数满足：最左边一位是奇数，第二位是偶数，且四位数字各不相同？
- A.1120
- B.1400
- C.1800
- D.2025
- E.2500
正确答案 · Correct Answer
B
解析 · Solution
解析整理中
继续练习