Aperson can copy final exams in 30 minutes using a new copy machine. using an old copy machine the same job takes 45 minutes. if the both copy machines are used. how long will it take to copy the final exams

Over the course of the school year, you keep track of how much snow falls on a given day and whether it was a snow day. your data indicates that of twenty-one days with less than three inches of snow, five were snow days, while of the eight days with more than three inches of snow, six were snow days. if all you know about a day is that it is snowing, what is the probability that it will be a snow day?