This is Dr Joseph Yeo Boon Wooi. He is the mathematics professor from the National Institute of Education (NIE) who sent the world into a tizzy with his "Cheryl's birthday" puzzle.
Described as in his 40s by The Straits Times, he is part of the panel for the Singapore and Asian Schools Math Olympiads (SASMO) that helps set the questions each year for student "mathletes".
The SASMO is the largest math competition here.
Dr Yeo is also the first author of the New Syllabus Mathematics used in secondary schools.
And yes, his birthday falls on July 16 -- the same as Cheryl's.
However, Dr Yeo did not specify exactly how he came up with the math question that stumped the world -- which he said is "not a new logic problem" -- other than he was following guidelines.
How did you come up with the question "Cheryl's birthday"?
I set the question based on guidelines given by SASMO.
This question, like all other questions we set, was vetted and approved by a panel of local and overseas experts from the SASMO Partners' League, which organises SASMO contests in their own countries.
"Cheryl's birthday" is not a new logic problem. There are various versions which others have modified. I am not aware of the original source. I modified it by changing the names, dates and context or storyline.
Photo by Dr Joseph Yeo Boon Wooi