Posted by Reiny on Thursday, May 17, 2007 at 10:14pm.
break it down into cases
at most one day of rain in 3 days to me means we could have:
norain norain norain > (1/3)^3 = 1/27
rain norain norain > 2/3(1/3^2 = 2/27
norain rain norain > same as above = 2/27
norain norain rain > same as above = 2/27
since there is an OR between these probabilities and there are no overlaps we simply add these
so 1/27 + 3(2/27) = 7/27
The probability of rain on any given day is 2/3. What is the probablity of at most one day of rain during the next three days...i don't get this problem plz explain the steps :)

math  anoneemose, Thursday, January 24, 2013 at 9:32pm
P(A and B) = P(A) * P(B)
2/3 = rain
1/3 = no rain
2/3 * 1/3 = 2/9