Dana AlKhayyal is planning her participation to the TV contest "Who Wants to

be Rich". In this contest Dana will be required to answer to a sequence of three

consecutive questions. If she provides a correct answer to a question then she

has to decide whether to go on to the next question or to stop playing. If she

stops playing after correctly answering the first question then she receives

10,000. If she stops after providing a correct answer to the second question

then she receives 50,000, and if she correctly answers the third question then

she will receive 250,000. However, if she provides a wrong answer to any of the

second or third question then she receives 5,000 (and no award if she fails at

the first question). Dana estimates that the probabilities that she will correctly

answer the first, second, third and fourth question are 0.80, 0.40, and 0.15,

respectively.

Dana wants to use a decision tree to decide how to proceed.