a*****g 发帖数: 1320 | 1 【 以下文字转载自 Seattle 讨论区 】
发信人: ashuang (不要迷恋哥,哥只是个传说), 信区: Seattle
标 题: mathscounts 数学题求助(3)
发信站: BBS 未名空间站 (Sun Oct 31 22:28:30 2010, 美东)
WHAT IS THE PROBABILITY THAT THE LAST THREE DIGITS OF A RANDOMLY SELECTED
PHONE NUMBER ARE ALL PRIME? EXPRESS YOUR ANSWER AS A COMMON FRACTION.
Please help to give the answer. Thanks, |
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