A question intended for math-savvy high school students in Singapore is stumping the world: when is Cheryl’s birthday?
Kenneth Kong — a television host in Singapore — shared a photo of the math problem that was originally part of the Singapore and Asian Schools Math Olympiads contest on his Facebook.
He said he and his wife had been in debate over the answer, and the world has been in a tizzy over the date of Cheryl’s birthday since.
Here’s the question reworded with clearer language, courtesy of The New York Times.
Albert and Bernard just met Cheryl. “When’s your birthday?” Albert asked Cheryl.
Cheryl thought a second and said, “I’m not going to tell you, but I’ll give you some clues.” She wrote down a list of 10 dates:
May 15 — May 16 — May 19
June 17 — June 18
July 14 — July 16
August 14 — August 15 — August 17
“My birthday is one of these,” she said.
Then Cheryl whispered in Albert’s ear the month — and only the month — of her birthday. To Bernard, she whispered the day, and only the day.
“Can you figure it out now?” she asked Albert.
Albert: I don’t know when your birthday is, but I know Bernard doesn’t know, either.
Bernard: I didn’t know originally, but now I do.
Albert: Well, now I know, too!
When is Cheryl’s birthday?
You can see why the viral math question threw everyone for a loop.
Took me a hot minute to figure out Cheryl's Birthday…
— alena (@alenakhxo) April 15, 2015
Still don't understand that Cheryl's birthday thing
— Lynelle D'Silva (@lynelle_dsilva) April 15, 2015
Does anyone understand rationally how anyone knows when Cheryl's birthday is?
— Principessa Gotica (@BadPrincipessa) April 15, 2015
I know when's Cheryl's birthday but won't wish her ever. #cherylsbirthday
— Saritha Iyer™ (@Starrysari) April 15, 2015
Took me 15 minutes to deduce when Cheryl's birthday was. Took me seconds to realise Albert and Bernard don't need that stress in their lives
— Kieran Lacey (@KieranLacey) April 15, 2015
Thankfully the question has been solved by more than a few people, and here’s the answer in video form.
Happy f—-ing birthday, Cheryl.
WATCH: