HMMT 二月 2013 · COMB 赛 · 第 1 题
HMMT February 2013 — COMB Round — Problem 1
题目详情
英文原题
A standard 52-card deck contains cards of 4 suits and 13 numbers, with exactly one card for each pairing of suit and number. If Maya draws two cards with replacement from this dec k, what is the probability that the two cards have the same suit or have the same number, but not b oth?
解析
英文解析
- A standard 52-card deck contains cards of 4 suits and 13 numbers, with exactly one card for eachpairing of suit and number. If Maya draws two cards with replacement from this deck, what is the probability that the two cards have the same suit or have the same number, but not both?
Answer: After drawing the first card, there are 12 other cards from the same suit and 3 other 15
12+352
cards with the same number, so the probability is .
52