Warren Buffett rejected this entrepreneur’s dinner invitation — but he did give her 3 pieces of advice

It's one thing plucking up the courage to ask someone to dinner. It's quite another to ask Warren Buffett.

But that's exactly what entrepreneur Kathy Xiaosi Gong, who was 24 at the time, did when she found herself in a room with the billionaire investor in Washington D.C.

"I saw my opportunity and I just had to take it," Gong told CNBC Make It at Money 20/20 in Singapore.