Warren Buffett used to ask college students this question—it can help you become richer and more successful

Warren Buffett is used to giving advice.

For decades, the Berkshire Hathaway chairman has sat before a packed arena during his company’s annual shareholder meetings, fielding investor questions on everything from artificial intelligence to the ins and outs of the insurance business to marriage advice.

In “Warren Buffett: A Life and Legacy,” which airs on Jan. 18 at 3 p.m. E.T. on CNBC, Becky Quick asks the Oracle of Omaha about some of the toughest questions and best advice he’s ever given. Buffett eventually arrives at a challenge he used to pose to college students.

Buffett would ask the students to consider a scenario in which, given a class of 300 or so of their peers, they could receive 10% of the lifetime earnings of five of them. Who would they choose — and why? And who would they sell short? The people you chose, he says, wouldn’t necessarily be the best looking or the smartest or the most athletic.

“Of course, I explained at the end, you can be the person that you would buy,” Buffett says. “There is nothing impossible. Because it isn’t whether you can throw a football 60 yards, and it … isn’t the one with the highest IQ. You can be one of the five.”