Many everyday decisions, like who will drive to lunch or who will pay for the coffee, are made by the toss of a (presumably fair) coin and using the criterion "heads, you will; tails, i will." this criterion is not quite fair, however, if the coin is biased (perhaps due to slightly irregular construction or wear). john von neumann suggested a way to make perfectly fair decisions, even with a possibly biased coin. if a coin, biased so that p(h)=0.4700 and p(t)=0.5300, is tossed twice, find the probability p(hh).