Probability of rain

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Probability of rain

by Uri » Sun Feb 01, 2009 2:28 pm
In Rwanda, the chance for rain on any given day is 50%. What is the probability that it rains on 4 out of 7 consecutive days in Rwanda?

a) 4/7
b) 3/7
c) 35/128
d) 4/28
e) 28/135

Official answer: [spoiler](C)[/spoiler]

Please explain the logic.

Thanks in advance.
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by Uri » Sun Feb 01, 2009 2:40 pm
I have got the answer from another post in this forum.
https://www.beatthegmat.com/semi-hard-pr ... t8877.html
Stuart has given an excellent explanation there.