$2\mathrm{.}7$ Exercises

Exercise $2\mathrm{.}1.$ To illustrate that simple rules cannot cope with uncertainty

reasoning, consider the following two cases:

$462$ Causal and Bayesian Networks

$($i$)$ I have an urn with a red ball and a white ball in it$.$ If I add a red ball

and shake it$,$ what is the certainty of drawing a red ball in one draw? If I

add a white ball instead, what is the certainty of drawing a red ball? If I

combine the two actions, what is the certainty of drawing a red ball?