# Basic Probability Questions, Part 3

• May 11th 2010, 09:58 AM
amysteriousman
Basic Probability Questions, Part 3
Last one :) thanks, guys

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?

7.) In a game of yahtzee you are left with (1,2,2,2,3) on your second roll. Show the procedure and calculate the "best" probability for tossing each of the following on your third and final roll:

a. full house (three of one kind and two of another kind)
b. small straight (four in a row)
c. yahtzee (all five are the same)
• May 12th 2010, 04:55 AM
CaptainBlack
Quote:

Originally Posted by amysteriousman
Last one :) thanks, guys

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?

You are given a very heavy hint here. Have you drawn the the contingency (probability) tree? Have you assigned each branch a probability? have you computed the leaf probabilities?

CB