Consider the following game: There are 2 boxes. Each box contains several en- velopes. Some envelopes have "you lose" written on them. The rest say "you win ...". How- ever, of the ones that say "you win ...", some contain only a piece of paper saying "... nothing", while each of the others contains a $5 bill.

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The first box contains 3 "you lose" envelopes and 2 "you win ..." envelopes. The second contains 1 "you lose" envelope and 3 "you win ..." envelopes. Each box contains only one $5 bill (in an envelope marked "you win ...").

Playing this game consists of choosing one of the 2 boxes at random, and then drawing one envelope at random from the chosen box. If the drawn envelope contains a $5 bill, the player gets to keep it, i.e. wins $5.

(a) Draw a probability tree to model one play of this game.