Sally plays two games against Martin.  In each game, Sally could win, draw or lose.  In each game they play,  the probability that Sally will win against Martin is $0.3$  the probability that Sally will draw against Martin is $0.1$  Work out the probability that Sally will win exactly one of the two games against Martin. 
Overseas Competition->Knowledge Point->Counting Modules->Statistics and Probability->Questions Involving Probability->Calculating the Probability by Using Law of Addition and Multiplication