On each of the first three days of January, there is a $\frac{1}{3}$ chance that it will snow where Bob lives. On each of the next four days, there is a $\frac{1}{4}$ chance that it will snow. What is the probability that it snows at least once during the first week of January?
+19 Take a look at https://web2.0calc.com/questions/the-probability-of-snow-for-each-of-the-next-three-days-is-frac-3-4-what-is-the-probability-that-it-will-not-snow-at-all-during-the-ne . It's very similar. If you still can't solve it, ask here.
