91 Detecting traces of TNT. University of Florida re -searchers in the Department of Materials Science and Engineering have invented a technique that rapidly detects traces of TNT ( Today , Spring 2005). The method, which involves shining a laser on a potentially contaminated object, provides instantaneous results and gives no false positives.

In this application, a false positive would occur if the laser detected traces of TNT when, in fact, no TNT were actually present on the object. Let A be the event that the laser light detects traces of TNT. Let B be the event that the object contains no traces of TNT. The probability of a false positive is 0. Write this probability in terms of A and B , using symbols such as “”, “  ”, and “ 

”.