SOLUTION: On a 21 problem test how many ways can a person get 7 right and 14 wrong?

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Question 1088574: On a 21 problem test how many ways can a person get 7 right and 14 wrong?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The order of answering the questions doesn't matter, so
this is a problem in combinations
C( 14,7 ) = +14%21+%2F+%28+7%21%2A%28+14+-+7+%29%21+%29+
C( 14.7 ) = +14%21+%2F+%28+7%21%2A7%21+%29+
C( 14,7 ) = +%28+14%2A13%2A12%2A11%2A10%2A9%2A8+%29+%2F+%28+7%2A6%2A4%2A3%2A2%2A1+%29+
C( 14,7 ) = +%28+13%2A11%2A10%2A9%2A8+%29+%2F+6+
C( 14,7 ) = +102960+%2F+6+
C( 14.7 ) = +17160+
There are 17,160 ways
get a 2nd opinion if needed