A cab drives down a pedestrian and leaves the scene. There are two taxi companies in the city: green taxis and blue taxis.

85% of taxis are green, 15% are blue.

A witness has identified the taxi as blue. It is assumed that witnesses are able to identify the correct taxi color in 80% of the cases and mistake 20% of the cases.

What is the likelihood that the taxi involved was blue? What mistakes are common to do in this type of problem? commentary.