A quiz consist of ten true-false questions how many possible answer keys are there?

The answer is not 20 I put that on the paper and it was wrong...





Can you please explain your answer to me when you tell me your answer.A quiz consist of ten true-false questions how many possible answer keys are there?
::sigh:: This is a statistics question, not some mind-trick puzzle. The answer isn't 20 due to there being many, many more possible keys out there (ever had a professor give out multiple tests? same scenario). For instance:


test 1: every answer is true


test 2: every answer but the first one is true


test 3: all but the 3 are true, etc...





The answer may be solved by a ';permutation'; or nPr on a calculator. This may also be represented as n!/(n-r)!





n is the 10 questions


r is the possible answers (2, T and F)





Solve:


10! / (10-2)!


=(10*9*8*7*6*5*4*3*2*1) / (8*7*6*5*4*3*2*1)


=3628800 / 40320


=214 answer keys may be availableA quiz consist of ten true-false questions how many possible answer keys are there?
10 answers. Each questions have two possible answers, true or false. Only one (either true or false) answer must be chosen for each questions. The reason is that the test is to ask you if the question is true or false. It cannot be both true and false at the same time.
an answer key is something which tells all the correct answers. so therefore, there is only one possible answer key as each question has to be true or false.