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Home > GC > Chapter 5 > Lesson 5.1.1 > Problem 5-9

5-9.

Earl hates to take out the garbage and to wash the dishes, so he decided to make a deal with his parents: He will flip a coin once for each chore and will perform the chore if the coin lands on heads. What he doesn’t know is that his parents are going to use a weighted coin that lands on heads of the time!  

  1. What is the probability that Earl will have to do both chores?

    Probability tree. Two branches with the outcomes of 0.80 and 0.20. The 0.80 branch splits into H branch. The H branch then splits into two branches H 0.80 and T 0.20. The 0.20 branch splits into T branch. The T branch then splits into two branches H 0.80 and T 0.20.

    Garbage

    top edge left

    top edge right

    Wash

    left edge top
     

    interior top left


    interior top right


    left edge bottom 

    interior bottom left blank

    interior bottom right blank

    What is the probability of flipping two heads in a row?

  2. What is the probability that Earl will have to take out the garbage, but will not need to wash the dishes?

    Use a tree diagram or two-way table.