One question deals with a difficult topic for Mr. Buffett: It addresses the Sequoia Fund, a mutual fund founded four decades ago to take on investors in what was then Mr. Buffett’s investment partnership, which was being wound down.

Since its inception, the Sequoia Fund has outperformed various stock market indexes. But it was severely wounded last year as shares in one of its biggest holdings, the drug maker Valeant Pharmaceuticals, plunged amid concerns about its business practices. Its high drug prices, its appetite for ever-bigger acquisitions and its ties to a dubious pharmacy affiliate all drew criticism.

Shares in Valeant have tumbled 67 percent so far this year, and its former chief executive was called to testify before Congress this week about the company’s drug-pricing policies.

Such was the turmoil at the mutual fund that two of its five independent directors abruptly resigned, apparently over its huge stake in Valeant, which at its peak represented 32 percent of the fund’s portfolio.

Turning quiet, Mr. Buffett spoke highly of Sequoia’s history. The mutual fund was founded by a close friend, the late William Ruane, and was the only one he recommended to his clients when he closed down his investment partnership.

But he also noted that the money manager responsible for Sequoia’s investment in Valeant, then-chief executive Robert Goldfarb, has left the fund. Such a concentrated bet was a huge mistake.

Mr. Buffett then openly derided Valeant, something that he had previously left to others. Mr. Munger famously and negatively compared the drug maker to the former conglomerate ITT last fall, drawing complaints from Valeant’s most outspoken backer, the hedge fund executive William A. Ackman.

In his remarks on Saturday, Mr. Buffett called Valeant “enormously flawed” and said that Berkshire had previously been asked to take a look at the company. It declined.

The billionaire went further, implying that the company was similar in some respects to “chain letter” companies designed to fool investors.

But leave it to Mr. Munger to toss off the most prickly description of the company: “Valeant was a sewer, and those who created it deserved the opprobrium they got.”