1. Jen will call Cathy on Saturday with a 60% probability. She will call Cathy on Sunday with an 80% probability. The probability that she will call on neither of the two days is 10%. What is the probability that she will call on Sunday if she calls on Saturday?

2. At a parking lot, there are 12 spaces arranged in a row. A man observed that there were eight cars parked and that the four empty spaces were adjacent to each other. Given that there are four empty spaces, is this arrangement surprising?

3. A fair die is rolled 12 times. Given that there are exactly two ones, what is the probability that there are exactly two sixes?

4. Jeff, Jen, and Cathy shoot at a bull's eye. They can hit the bull's eye 70%, 80%, and 75% of the time, respectively. One of the three is known to have hit the bull's eye. Find the probability that it was Jen.