How many ways are there to pick 10 balls from large piles of identical red, green and blue balls, plus one pink ball, one black ball, and one yellow ball?
How many ways are there to pick 10 balls from large piles of identical red, green and blue balls, plus one pink ball, one black ball, and one yellow ball?
Here what you will find in 'back-of-the-book'.
$\displaystyle \sum\limits_{k = 0}^3 {\binom{3}{k}\binom{12-k}{2}}
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