We're in assignment one, most of the questions are just there for you to think about and to discuss with your fellow students. And I'm going to leave you to do that and sort them out on your own, discuss them on the forums or with whatever group you've put together. And please do put together a group. What I will do is say a little bit about question 8. Well, question 8 is related to Euclid's proof that there are infinitely many primes. Another crucial point in that proof, we looked at this number where p1 though pn enumerates the first n primes. We multiply them together and we add 1. And I mentioned during the proof that this number is not always prime. And question 8 asks how would you prove that it's not always prime? And the answer is you have to find a number, n, such that when you do multiply the first n primes and add 1, it's not prime. Well, how would you go about doing that? Well, the most obvious way is you start searching. So you would start by looking at the first two primes, say, multipy them together, add 1, you get 7. Well, that is prime. Try another one. (2 x 3 x 5) + 1. That's 31. That's also a prime. Let's try another one. (2 x 3 x 5 x 7) + 1. That's 211. That's also a prime. At this point you're probably starting to lose heart, but if you keep on just two more primes 2, 3, 5, 7, 11, 13 multiplied together and add 1. You end up with 30,031, which is not prime because it's a multiple of 59 and 509. Okay? So here we've got an example of a number of this form which is not prime. And in order to show that not every number of that form is prime, all you have to do is find a single example of a number in that form which isn't prime. And we've done it. So, that's the answer to question 8. That's how you prove that these numbers are not always prime, okay? Well, that's really all I wanted to say about assignment one. Assignment two has a little bit more meat to it in a sense that there are more things that I'll need to show you.