1. There are two flasks, labelled A and B A tastes like water and will not immediately harm you if you drink it. However, if you drink more than a litre of it, you have a 1 in 4 chance, in five years’ time, of developing a terrible liver disease that will kill you. B tastes ghastly. If you drink one mouthful it will kill you painlessly in 5 minutes. Which is more dangerous? Why?
2. Things to think about You probably think that B was the most dangerous as it would definitely kill you. However, the source would be rapidly identified and nobody else would die. Flask A could go on killing people for many years as it would be very difficult to find the cause 5 years later. This is the problem with medical research. Many people claim that mobile phones can cause illness. Proving this link (one way or the other) is extremely difficult.
