You are serving cookies at a party. The party tray holds 8 chocolate chip cookies, 5 sugar cookies, and 7 oatmeal raisin cookies. What is the probability that the first person will take and keep a sugar cookie and the second person will take a chocolate chip cookie? Write your answer as a simplified fraction.
There are a total of 8 + 5 + 7 = <<8+5+7=20>>20 cookies.
The probability that the first person takes and keep a sugar cookie is 5/20.
Now, there are 7 chocolate chip cookies left after the first person takes, so the probability that the second person takes a chocolate chip cookie is 7/19.
Therefore, the probability that the first person takes a sugar cookie and the second person takes a chocolate chip cookie is (5/20) * (7/19) = 35/380.
The simplified fraction for this probability is 7/76. Answer: \boxed{\frac{7}{76}}.
When a coin is flipped three times, the possible outcomes are:
HHH
HHT
HTH
HTT
THH
THT
TTH
TTT
Out of these eight outcomes, there are three outcomes with exactly one tail:
HHT
HTH
THH
So, there are \boxed{3} outcomes in the event "exactly one tail" when a coin is flipped three times.