Duchess Catherine took part in a treasure hunt when she visited the Docklands Sailing and Watersports Centre on Friday.
The 35-year-old royal was joined by school children in East London taking part in the hunt, which used QR codes to activate a science question.
During the visit, the Duchess of Cambridge met schoolboy Rafi Ahmed, who asked her how many cars she had.
Recalling their conversation, he said: "I said 'how many cars do you have?' She said she had a Land Rover. She asked me 'what's your favourite car?' I said a Lamborghini. I felt like I was going to be famous."
And in a conversation with 10-year-old Katie Lam, the Duchess asked her: "Are you going out [sailing] later? Have you got sailing stuff with you?"
Speaking about her meeting with the Duchess, Katie added: "She looked even better in real life than in photos. It was amazing to meet her."
Duchess Catherine also spoke to Sir Ben Ainslie, the British Olympic sailing champion, through video link as he is still in Bermuda after losing in America's Cup yachting race.
She told him: "Commiserations, obviously, but really well done. We've been watching with really keen interest.
"Both William and I have been glued to the telly. Well done to you guys. I gather now you're on to the next thing."
Ben also took questions from the crowd of young people gathered.
Speaking about the Duchess' visit, he said: "It's fantastic to see the work the trust has been able to put together, it's great to have your help with that."
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