HMMT 二月 2001 · 冲刺赛 · 第 7 题
HMMT February 2001 — Guts Round — Problem 7
题目详情
英文原题
- [5] Suppose a , b , c , d , and e are objects that we can multiply together, but themultiplication doesn’t necessarily satisfy the associative law, i.e. ( xy ) z does not necessarilyequal x ( yz ). How many different ways are there to interpret the product abcde ?
解析
英文解析
- [5] Suppose a , b , c , d , and e are objects that we can multiply together, but themultiplication doesn’t necessarily satisfy the associative law, i.e. ( xy ) z does not necessarilyequal x ( yz ). How many different ways are there to interpret the product abcde ?
Solution: C (number of letters − 1) = C (4) = 14 .