Combinations and Investment Strategies

Baker · science forum beginner Joined: 19 Jun 2006 Posts: 2

Here's a problem that is simply blowing me away. I have an idea how to
approach it but I keep coming up with the wrong answer.

Here's the problem:

I have $20 thousand dollars that must be invested in 4 possible
opportunities. Each investment must be an integral unit of 1000 dollars.
In Additionally there is a minimal amount of 2, 2, 3, and 4 thousand
dollars for each of the 4 investments. How many different investment
strategies are available if investments must be made in at least 3 of the
4 opportunities ??

According to the book the correct answer is 552 possible investments.
I get everything but that answer despite the fact that I was able to
answer every other theoretical question and problem in the chapter
correctly.

Can anyone figure this out ?? Thanks...

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