how do I write a business solution of at least 350 words addressing a business communication problem?

First you need to identify the business communication problem you want to address. Then decide on three or four ways to solve this problem.

I suggest you make an outline, briefly describing the problem and its solution in your first paragraph. Your next paragraphs should detail your proposed solutions. Finally, sum up your suggestions in the last paragraph.

These sites may give you some ideas.

http://www.businesstown.com/people/communication-improving.asp

http://pharmrep.adv100.com/pharmrep/data/articlestandard/pharmrep/292004/104024/article.pdf