Last one

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6.) John figures that if he stays home for the weekend and studies for his Math exam he will have a 70% change of getting an A. If he does not stay home he figures he still has a 20% chance for an A. John's problem is that he plans to attend a beach party that weekend if it doesn't rain. The weather forecast shows a 40% chance of rain over the weekend. Draw a probability tree diagram for John and answer the following questions. (hint: 1st selection home or beach, 2nd selection A or not A)
a. what is John's chance of getting an A?
b. what is John's chance of not getting an A?
c. if John decides to go to the beach regardless of the weather, what is his chance of an A?