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If you select a student at random, what is the probability that the student has gone to...
If you select a student at random, what is the probability that the student has gone to the beach but not to the amusement park?
Suppose that among all U.S students, 80% have gone to an amusement park and 45% have gone to the beach. Only 15% have done neither.
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High School Teacher
If you know there are 100% of people to chose from, and 15% have done neither, then you have 85% left. Since 80% have gone to an amusement park, only 5% have not. These 5% have gone to the beach only. The breakdown would be as follows:
beach only: 5%
amusement park, only: 40%
Posted by mcetner on February 6, 2009 at 9:22 PM (Answer #1)
There's 100% of students to choose from. Since you know that 15% of them did not do either of these places, then 85% of them might have gone to the beach or the amusement park.
Since you know that 80% of the students went to the amusement park, only 5% of them didn't, so they must have went to the beach.
The P(students went to beach is 5/100= 1/20
Posted by revolution on July 21, 2010 at 10:10 PM (Answer #2)
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