correction to text for question 3(a)

I have not been careful enough regarding point 3(a). Mea culpa! The correct text there should be:

If $\tau$ is given the flat prior on $1,\ldots,n$ (each position having prior probability $1/n$), find an expression for the posterior distribution $\pi(\tau|\data)$. 

This message is also given under the "Exam Project, December 2015" umbrella.