Practice Exercises for Probability

Directions: Read each question below. Select your answer by clicking on its button. Feedback to your answer is provided in the RESULTS BOX. If you make a mistake, choose a different button.

1.  Which of the following is an impossible event?
   
 
 Choosing an odd number from 1 to 10.
 Getting an even number after rolling a single 6-sided die.
 Choosing a white marble from a jar of 25 green marbles.
 None of the above.

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2.  Which of the following is the sample space for choosing a letter from the word LIBRARY?
   
 
 {I, A}
 {L, I, B, R, A, R, Y}
 {L, I, B, R, A, Y}
 None of the above.

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3.  What is the probability that a single card chosen from a deck is not an ace?
   
 

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None of the above.

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4.  Which of the following is a certain event?
   
 
 Choosing a teacher from a room full of students.
 Choosing an odd number from the numbers 1 to 10.
 Getting a 4 after rolling a single 6-sided die.
 None of the above.

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5.  There are 4 parents, 3 students and 6 teachers in a room. If a person is selected at random, what is the probability that it is a teacher or a student?
   
 

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None of the above.

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6.  In a high school computer class there are 15 juniors and 10 seniors. Four juniors and five seniors are boys. If a student is selected at random, then what is the probability of selecting a junior or a boy?
   
 

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None of the above.

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7.  A jar contains 5 red, 3 green, 2 purple and 4 yellow marbles. A marble is chosen at random from the jar. After replacing it, a second marble is chosen. What is the probability of choosing a purple and then a red marble?
   
 

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8.  Three cards are chosen at random from a deck without replacement. What is the probability of choosing an eight, a seven and a six, in order?
   
 

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None of the above.

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9.  In a shipment of 25 DVD Players, 2 are defective. If 2 DVD Players are randomly selected and tested, what is the probability that both are defective if the first one is not replaced after it has been tested?
   
 

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None of the above.

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10.  In a school, 48% of the students take a foreign language class and 19% of students take both foreign language and technology. What is the probability that a student takes technology given that the students takes foreign language? (Round your answer to the nearest percent.)
   
 
67%
253%
40%
None of the above.

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