Updated 15 April 2015

Can you solve this grade 8 maths problem?

The world is gripped by a maths question from a Singapore school exam that most adults can't answer. Can you?


People grasp maths in varying degrees, some people just get algebra, trigonometry and calculus where as some others really don't and are left at the back of the class reciting their times tables. Unfortunately, South Africa tends to see a lot more of the latter than the former, with one report from the World Economic Forum suggesting that SA actually has the world's worst maths education. 

Singapore, on the other hand, is often considered to produce the world's best maths students, and we're about to see why. 

Recently, a photo started making the rounds on the internet purporting to show a question from an exam at a school in Singapore. Initially reported as being for 10 year olds, it was later clarified as a question aimed at 14 year olds. Either way, internet reaction suggests that most grown adults are incapable of getting the question, with its mix of logical reasoning and mathematical knowledge, correct.

We've posted the picture below and, to paraphrase the Guardian, are you smarter than a 14-year old from Singapore?

If you can't see the image, or find the wording confusing, I've rewritten it below as per Kenneth Chang, the New York Times' science editor, it reads as such:

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?

Have a good hard think about it, and post your answer in the comments, with an explanation, if you think you've got it. No googling! 

After that, or if you simply have no idea, the answer is here.

Good luck!

Read more:

Fast food made lead to poorer school results 

The influence of genes on maths and reading 

Preschool counting affects future maths ability

Image credit: Maths by Shutterstock


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