第二題:What if not all money need be invested? 可這樣理解：

來源: 於 2010-09-08 10:37:04 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

Investing 16 thousand dollars to 5 possible opportunities. To some of opportunities, 0 could be invested.

The fifth opportunity is investor's wallet. There is still some money in investor's wallet, not be invested yet.

So result is C(16+5-1,5-1) = C(20,4)