1.I have an unlimited supply of standard 6-sided dice. What's the fewest number of dice that I have to simultaneously roll to be at least 90% likely to roll at least one 6? You may use a calculator to help you with the computations if you like -- in fact you'll almost certainly want to -- but your final answer should be a positive integer, and you should explain how you got it.
2.On each of the first three days of January, there is a chance that it will snow where Bob lives. On each of the next four days, there is a chance that it will snow. What is the probability that it snows at least once during the first week of January?