It's not the type of question that law students typically field: If you owned 5 percent of Geico Corp.'s stock valued at $55 a share, and Warren Buffett offered to buy them at a price of $70 a share, would you sell?

One hundred Georgetown University Law Center students assembled last month in a sprawling lecture hall took to their laptops and smartphones to weigh in via an online poll conducted by business professor Sandeep Dahiya. The results came back within seconds: Nearly three-quarters of the students said they would sell. The Buffett/Geico case study was part of Dahiya's crash course in the time-value of money — the basic financial theory that money today has different buying power over time given interest and inflation.