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Sheet # 22/Probability

Name: _____________________ Date_____________


1) Two black marbles and one white marble are in a box. Without looking inside the box, you take out one marble. What is the probability a black marble will be picked? a white marbled will be picked?

 

2) Suppose you have tossed a coin 9 times and it has shown heads each time.

a) What is the probability that the coin will show a tail on the tenth toss?

 

b) Does the outcome of the first 9 tosses have any effect on the outcome of the tenth toss?

 

3) There are 25 students in a class, of whom 10 are girls and 15 are boys. The teacher has written the name of each student on a separate card. If a card is drawn at random, what is the probability that the name written on the card is the name of a girl? of a boy?

 

 

4) Suppose a box contains 48 marbles, Eight of the marbles are black and forty of the marbles are white. What is the probability you would choose a black marble or a white marble?

 

 

5) In a newspaper you read:  "Mr. Jackson has 50-50 chance of winning the election."  What is the probability that Mr. Jackson will win?