In this edition of The Motley Fool's "Ask a Fool" series, Motley Fool One analyst Jason Moser takes a question from a Fool reader who asks: "I'm just starting to invest into a 401(k) at work. I know it's Foolish to be diverse, but how many funds should I invest in?" Jason believes that one of the most important questions to answer first is whether an investor is looking to grow or protect his wealth. From there exist a number of options, but giving one's self exposure to small-, mid-, and large-cap stocks along with emerging/international ones can offer ample diversity while maximizing opportunity.