SOLUTION: Evaluate C 15 9 Answers to this question would be much obliged..the 15 is supposed to be on left side of the C,sorry.

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Question 136121: Evaluate

C
15 9
Answers to this question would be much obliged..the 15 is supposed to be on left side of the C,sorry.
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
The number of combinations of 15 things taken 9 at a time is given by 15%21%2F%289%21%2815-9%29%21%29

Note that 15! = 15 * 14 * 13 * 12 * 11 * 10 * 9!, and 15 - 9 = 6, so:

%2815+%2A+14+%2A+13+%2A+12+%2A+11+%2A+10+%2A+9%21%29%2F%289%21%286%2A5%2A4%2A3%2A2%29%29

%2815+%2A+14+%2A+13+%2A+12+%2A+11+%2A+10%29%2F%286%2A5%2A4%2A3%2A2%29 (4 * 3 = 12, so eliminate 4 and 3 in the denominator and 12 in the numerator)

%2815%2A14%2A13%2A11%2A10%29%2F%286%2A5%2A2%29 (6 is 2*3, 3*5 is 15 eliminating that factor, leaving a 2 and a 2 in the denominator, 2 into 14 is 7 and 2 into 10 is 5)

%287%2A13%2A11%2A5%29

5005

Or you can do it the hard way:
1307674368000%2F%28%28362880%29%28720%29%29=5005