SOLUTION: https://vle.mathswatch.co.uk/images/questions/question17972.png please help

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Question 1118088: https://vle.mathswatch.co.uk/images/questions/question17972.png please help
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
The probability of rain is %2270%25%22=70%2F100=0.7 on each day for Friday Saturday and Sunday.
That means that the probability that it will not rain is %2230%25%22=30%2F100=0.3 for each day.

a) The probability that it will rain all 3 days is
0.7%2A0.7%2A0.7=highlight%280.343=%2234.3%25%22%29 .

b) The probability that it will rain on exactly two consecutive days between Friday and Sunday includes two cases:
1) either the day it does not rain is Sunday, but it rains the two days before, or
2) it does not rain on Friday, and then it rains the two days after that.
The probability that it will rain on Friday and Saturday, but not on Sunday is
0.7%2A0.7%2A0.3=0.147 .
The probability that it will rain on Saturday and Sunday, but not on Friday is also
0.147 .
So, the probability that it will rain on exactly two consecutive days between Friday and Sunday is
0.147%2B0.147=highlight%280.294=%2229.4%25%22%29 .