返回题库

HMMT 二月 2001 · 冲刺赛 · 第 7 题

HMMT February 2001 — Guts Round — Problem 7

专题
Discrete Math / 离散数学
难度
L3
来源
HMMT

题目详情

  1. [5] Suppose a , b , c , d , and e are objects that we can multiply together, but the multiplication doesn’t necessarily satisfy the associative law, i.e. ( xy ) z does not necessarily equal x ( yz ). How many different ways are there to interpret the product abcde ?
解析
  1. [5] Suppose a , b , c , d , and e are objects that we can multiply together, but the multiplication doesn’t necessarily satisfy the associative law, i.e. ( xy ) z does not necessarily equal x ( yz ). How many different ways are there to interpret the product abcde ? Solution: C (number of letters − 1) = C (4) = 14 .