Event: an action or occurrence; each event has its own probability
Probability: the likelihood that an event will occur, expressed as a percentage or fraction
Probability Form: Part / Whole, or # of an outcome / # of total outcomes
Probability of 1: expression that an event has a 100% chance to happen
Probability of 0: expression that an event has a 0% chance to happen

SAMPLE PRACTICE QUESTIONS FOR PROBABILITY

1. A mailwoman delivers mail to 40 houses in the morning and to 80 houses in the afternoon. If she lost her purse, what is the probability that     she left it at one of the houses in the morning?

      Solution
      A) Probability = part / whole = # morning houses / # total houses
          40/120 = 1/3 or 33.33%

2. A snack mix contains exactly 43 raisins, 26 peanuts, 14 walnuts, and 17 slices of dried banana. If a person randomly selects one item     from the snack mix, what is the probability that he/she will not pick a nut?

     Direct Solution
      Prob. = part / whole= # fruit pieces (not nuts) / # total items
      (43 + 17) / (43 + 26 + 14 + 17) = 60/100 = 3/5
      
      Indirect Solution
      Prob. = part / whole = # nuts / # total items
      (26 + 14) / (43 + 26 + 14 + 17) = 40/100 = 2/5
      Probability of picking a nut is 2/5, so probability of not picking one = 1 - 2/5 = 3/5.

Math: Probability Problems

—Math Terms for Probability Questions

—Sample Practice Questions

—Practice Questions

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PROBABILITY MATH QUIZ

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