Editor's note: Jim Cramer answers questions below.

Given that Caterpillar (CAT) generates about 50% of its revenue overseas, is that a good substitute for having 20% of your holdings in foreign stocks?

-- Dave D.

Jim Cramer: You're correct that this is definitely a step in the right direction. Still, with active trading in many foreign stocks through American depositary shares, I'd prefer to see investors own at least one foreign-based company in the portfolio. Two such stocks I own for my charitable trust are Toyota Motor ( TM) and Diageo ( DEO).

Which energy stock do you like better, Marathon Oil (MRO) or Devon Energy (DVN)?

-- Stephen G.

Jim Cramer: First of all, these companies serve two different niches of the energy market, so be careful when you compare them head-to-head. Marathon is a major integrated energy company, which means it both produces oil and natural gas from the ground and refines it into other products such as gasoline. On the other hand, Devon is a pure-play exploration company with a lot of exposure to unhedged natural gas. With that in mind, both stocks appear attractive, if energy commodity prices truly have bottomed out for the time being.

What's your formula for figuring out a reasonable P/E ratio for high-growth stocks such as Google (GOOG) or New York Stock Exchange (NYX)?

-- Shelley L.

Jim Cramer: At the simplest level, I believe that stocks like these deserve to trade at two times their growth rate. That said, you must keep in mind that this area of the market is very fluid and that the underlying earnings expectations can change in a heartbeat.

I know that you have not been a big fan of Alcoa (AA) in the past. Even so, do you think that the stock is just too cheap to ignore these days?

-- Tim C.

Jim Cramer: I'm still not a big fan of CEO Alain Belda and the aluminum company. That said, the stock is trading at just 11 times expected full-year earnings, and Alcoa continues to use excess cash flow to pay dividends and to buy back stock. The recent consolidation in the metals space has left only a few major players, and I would not be surprised if someone came in and bought out the company at these discounted levels.
At the time of publication, Cramer was long NYSE Group, Toyota Motor and Diageo.

Jim Cramer is a director and co-founder of TheStreet.com. He contributes daily market commentary for TheStreet.com's sites and serves as an adviser to the company's CEO. Outside contributing columnists for TheStreet.com and RealMoney.com, including Cramer, may, from time to time, write about stocks in which they have a position. In such cases, appropriate disclosure is made. To see his personal portfolio and find out what trades Cramer will make before he makes them, sign up for Action Alerts PLUS. Watch Cramer on "Mad Money" weeknights on CNBC. Click here to order Cramer's latest book, "Mad Money: Watch TV, Get Rich," click here to order his book, "Real Money: Sane Investing in an Insane World," click here to get his second book, "You Got Screwed!" and click here to order Cramer's autobiography, "Confessions of a Street Addict." While he cannot provide personalized investment advice or recommendations, he invites you to send comments on his column by clicking here.

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