document.write( "Question 88730: A test has 10 true/false questions. How many different tests can be turned in to the teacher? \n" ); document.write( "
Algebra.Com's Answer #64494 by bucky(2189)\"\" \"About 
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The first question could be answered either true or false.
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\n" ); document.write( "If you answered true on the first question, you could answer either true or false on the
\n" ); document.write( "second question.
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\n" ); document.write( "If you answered false on the first question you could answer either true or false on the
\n" ); document.write( "second question.
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\n" ); document.write( "So after two questions you have four possible situations:
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\n" ); document.write( "True & then True
\n" ); document.write( "True & then False
\n" ); document.write( "False & then True
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\n" ); document.write( "Now for each of those 4 possibilities, you could answer either true or false on the third question.
\n" ); document.write( "So after 3 questions you would have 8 possible test answers ... 4 * 2.
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\n" ); document.write( "And for each of the 8 possible answer situations on the third question, you can answer either
\n" ); document.write( "true or false on the fourth question. This will give you 8 * 2 = 16 possible answers after
\n" ); document.write( "the fourth question.
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\n" ); document.write( "By now you have probably noticed the pattern. Each additional question increases the number
\n" ); document.write( "of possible answer configurations by a factor of 2.
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\n" ); document.write( "This pattern is reflected by the equation:
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\n" ); document.write( "Number of different tests = 2^n
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\n" ); document.write( "where n represents the number of questions on the test.
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\n" ); document.write( "If there were just 1 question on the test there would be 2^1 possible answers (either true
\n" ); document.write( "or false). If there were 2 questions on the test, the number of possible answer combinations
\n" ); document.write( "would be 2^2 or 4. Similarly for 3 questions there would be 2^3 = 8 possible combinations.
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\n" ); document.write( "Extending on this pattern, for a 10 question test there would be 2^10 possible combinations
\n" ); document.write( "of answers. And 2^10 = 1024 possible answer combinations. That means that the teacher
\n" ); document.write( "could possibly receive 1024 tests that are all different by at least one answer.
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\n" ); document.write( "Hope this provides you with a way of figuring out a process for solving questions
\n" ); document.write( "such as this one.
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