Epic Cooking: You may not know this, but a friend and I like to do 'epic cooking'. Lately this has involved making stew, curry, and tomato sauce, often on the scale of more than 100 kg and then canning it through a pressure canning process. Admittedly, it is a lot of work, but it does leave one with quite a quantity of stew, tomato sauce and curry - which is nice for the Kingston winters.

Suppose I have 60kg of beef, 100kg of tomatoes, 40kg of potatoes and an endless quantity and variety of spices. My standard tomato sauce recipe requires 1 kg beef, 5 kg tomatoes and no potatoes, my curry recipe is 2 kg of each of beef, tomatoes and potatoes (you laugh now, but it is awesome!) and my stew recipe is 3 kg beef, 1 kg tomatoes and 2 kg potatoes.

For each question below, be sure to explain and justify how you reached your conclusion. 1 .Tracy hates it when I have left over ingredients, so how much of each should I plan to make?

2. Before I start, I ask Tracy to call my friend's wife to ask her to ask him to pick up some extra tomatoes. If there is a 10% chance of the message getting lost as each person tries to tell the next person, what is the chance it will get messed up either once or three times somewhere along the way? How did you model this?

3. Naturally, he shows up with an extra 20 kg of potatoes. What should I do now? Do I have a problem?