The question was: "Why is it harder to recall smell than other senses like hearing and sight?"
And that was the right answer for 18-year-old Raffles Institution graduate Deanna See, who won the latest annual Molecular Frontiers Inquiry Prize.
It is awarded by the Molecular Frontiers Foundation to the top 10 young people worldwide - five boys and five girls - for asking scientific questions which they can later choose to research.
"After submitting questions three years in a row, I realised (it is better) not to think too hard about it," she said. "I keep a notebook of questions. It was one of those that just popped into my head, so I wrote it down. I didn't expect to win at all."
Deanna, who received a medal and certificate, called the competition "an incentive to keep asking questions", which encourages students "to see it rather as a thrill, or excitement, instead of fear".