1/42
First, find the probability of Willie winning the grand prize. He has 1 ticket out of the 7 total tickets, so the probability is 1/7.
Now, find the probability of Emily winning the second prize. After the grand prize winner has been announced, there are only 6 tickets left. Emily has 1, so the probability is 1/6.
Finally, multiply the two probabilities together to find the probability that they will both happen together. To multiply fractions, multiply the numerators together and multiply the denominators together. This leaves us with (1 * 1) / (7 * 6), which is easy to simplify to 1/42, which is the final probability.