SOLUTION: A teacher makes a multiple-choice quiz with 12 questions. 3 answers are A, 3 answers are B,2 answers are C and 4 answers are D. How many possible answer keys are possible I thi

Algebra ->  Permutations -> SOLUTION: A teacher makes a multiple-choice quiz with 12 questions. 3 answers are A, 3 answers are B,2 answers are C and 4 answers are D. How many possible answer keys are possible I thi      Log On


   



Question 1101050: A teacher makes a multiple-choice quiz with 12 questions. 3 answers are A, 3 answers are B,2 answers are C and 4 answers are D. How many possible answer keys are possible
I think you can solve it like this but am not sure:
12C3 x 9C3 x 6C2 x 4C4
= 277200 keys

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
for this problem, we use combinatorial counting
for the first question there are 12 possible choices, for the second question there are 11 choices, for the third question there are 10 possible choices, ...
:
Note that I assume there are NO restrictions on the placement of the answers
:
12! = 479001600
:
now we must divide 479001600 by the number of permutations we can not distinguish
:
*************************************************************
479001600 / (3! * 3! * 2! * 4!) = 277200 possible answer keys
*************************************************************
: