The weather forecast for the weekend is a 46% chance of rain for Saturday and a 54% chance of rain for Sunday. If we assume that consecutive days are independent events.What is the probability that it rains over the weekend (either Saturday or Sunday)?
+23246 Probability that it will rain:
-- on both Saturday and Sunday : 0.46 x 0.54 = 0.2484
-- on Saturday but not on Sunday: 0.46 x 0.46 = 0.2116
-- on Sunday but not on Saturday: 0.54 x 0.54 = 0.2916
On Saturday or Sunday (inclusive or -- possibly both) = 0.2484 + 0.2116 + 0.2916 = 0.7516
On Saturday or Sunday (exclusive or -- one or the other, but not both) = 0.2116 + 0.2916 = 0.5032
This may be somewhat confusing because "not Sunday" = 1.00 - 0.54 = 0.46 (the same as "on Saturday") and
"not Saturday" = 1.00 - 0.46 = 0.54 (the same as "on Sunday").
