Problem Solving
试题详情
题目：
A box contains 100 balls, numbered from 1 to 100. If three balls are selected at random and with replacement from the box, what is the probability that the sum of the three numbers on the balls selected from the box will be odd?
选项:
A、1/4
B、3/8
C、1/2
D、5/8
E、3/4
答案:
C
提问：
请解答一下此题，我知道三个数要么是奇数+奇数+奇数，要么是偶数+偶数+偶数，三个都是奇数的概率我理解是1/2*1/2*1/2，偶数的情况我不太明白，请解答[img=/resource/2019-01/4085-1547312708.jpg]
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1
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