If an experiment consists of five outcomes with p(o1) = 0.10, p(o2) = 0.20, p(o3) = 0.30, p(o4) = 0.25, then p(o5) is

.p(o5) is equal to 0.15. This can be determined because p(o5)= 1- [p(o1)+ p(o2)+ p(o3)+ p(o4)], which is equivalent to p(o5)= 1- (0.10+0.20+0.30+0.25), which gives you a p(o5) value of 0.15.