On each of the first three days of January, there is a 1/2 chance that it will snow where Bob lives. On each of the next four days, there is a 1/3 chance that it will snow. What is the probability that it snows at least once during the first week of January?
+2668 It is easier to count for what we don't what and subtract that from 1.
The probability that there will 0 days of snow is: 123×234=281
Thus, the probability that it will snow for at least 1 day of the week is: 1−281=7981
