Chapter 13 - General Rules of Probability - Apply Your Knowledge - Page 311: 13.8

Let Role Playing Game = R Strategy Game = S P(R) = 0.139 P(S) = 0.354 $P(S^{c}) = 1 - P(S)$ = 1 - 0.354 = 0.646 $P(R∩S^{c}) = 0.139\\ P(R|S^{c}) = P(R∩S^{c}) / P(S^{c})$ = 0.139 / 0.646 = 0.215

Let Role Playing Game = R Strategy Game = S P(R) = 0.139 P(S) = 0.354 $P(S^{c}) = 1 - P(S)$ = 1 - 0.354 = 0.646 $P(R∩S^{c}) = 0.139\\ P(R|S^{c}) = P(R∩S^{c}) / P(S^{c})$ = 0.139 / 0.646 = 0.215