(CNN) Bill Gates made some eyebrow-raising claims about President Donald Trump on Thursday, saying he doesn't know the difference between two sexually transmitted diseases and that it was "scary" how much Trump knew about Gates' daughter's appearance.

Taking audience questions about his interactions with Trump at a Bill & Melinda Gates Foundation meeting, the former Microsoft honcho said he first met Trump in December 2016. He told the audience that Trump had previously come across his daughter, Jennifer, at a horse show in Florida.

"And then about 20 minutes later he flew in on a helicopter to the same place," Gates said, according to video of the event broadcast by MSNBC late Thursday. "So clearly he had been driven away but he wanted to make a grand entrance in a helicopter.

"Anyway, so when I first talked to him, it was actually kind of scary how much he knew about my daughter's appearance. Melinda (Gates' wife) didn't like that too well."

Gates also said he discussed science with Trump on two separate occasions, where he says the President questioned him on the difference between HIV and HPV.

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