CLOSE
iStock
iStock

Try Solving This Riddle From a High School Math Competition

iStock
iStock

Math olympiads feature some of the brightest minds to enter high school. The problems given to competitors are meant to be tricky, but there’s one question that’s so notorious it even has its own Wikipedia page.

The "Cheryl’s Birthday" riddle first appeared on a math olympiad test given to students in Singapore. Local television presenter Kenneth Kong posted a picture of the original text on Facebook in 2015. The clunky English makes for a riddle that's hard to decipher, so The New York Times published an edited version that reads as follows:

"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?"

If you read through this quickly, it’s easy to get lost. How is it possible to guess someone’s birthday when you only have one half of the date? And how could Albert and Bernard help each other guess correctly without sharing their intel out loud? The secret lies in the possible dates Cheryl chooses to share.

In her list, every day is repeated once except for the 18th and the 19th—so if she had whispered “18” in Bernard’s ear he would immediately know her birthday was June 18, and if she’d whispered “19” he’d know it was May 19. Bernard confirms it couldn’t be either of those dates when he says he “didn’t know originally.” That means June and May are no longer options for Albert, which narrows it down to five possibilities: July 14, July 16, August 14, August 15, and August 17.

When Bernard says “I didn’t know[…]but now I do” that disqualifies 14, because in that case he would have two potential answers (July 14 and August 14) to choose from. These leaves three dates—July 16, August 15, and August 17—that could be correct. When Albert says, “Well, now I know too!” he eliminates July from the equation because that’s also a case where he’d be left with two options. July 16 is therefore the one true answer.

Does your head hurt yet? Unfortunately, math problems intended for grade-schoolers in Singapore don’t get much simpler. Check out this perplexing homework problem given to first-graders if you need convincing.

[h/t The New York Times]

nextArticle.image_alt|e
NBC
arrow
Pop Culture
Solve a Murder Mystery (and Eat Cheesecake) with The Golden Girls
NBC
NBC

Something is rotten in the city of Miami. A murder has been committed—and nobody knows who’s behind the dastardly crime. The police are likely no match for the killer, so it’s up to the Golden Girls characters to combine their wits (over cheesecake, of course) to crack the case. But they can’t do it without your help.

That’s right: Peddler’s Village, a quaint shopping village in Lahaska, Pennsylvania, is now offering a Golden Girls Murder Mystery dinner and show every Friday and Saturday night through August 25, 2018. The whodunit takes place at Peddler's Pub at the Cock 'n Bull Restaurant, at 7 p.m.

While the major plot details have been kept under wraps (it is a murder mystery, after all), we do know that Dorothy, Blanche, Rose, and Sophia have "invited a couple of well known detectives to join the party and discuss their famous capers." And given that the show is titled "The Golden Girls: The Curse of Jessica Fletcher," we can only guess (and hope) that an amateur sleuth from Cabot Cove, Maine will be making an appearance.

It's not the first time Peddler's Pub has hosted the gals from Miami; the current show is a sequel of sorts to the original Golden Girls Murder Mystery that Peddler's Pub put on back in 2016. Fun fact: Mental Floss Editor-in-Chief Erin McCarthy beat out a room full of other Betty White sangria-drinking armchair detectives to correctly solve the mystery during its original run. (She has the mug to prove it.)

Tickets are $69.95 per person, and you can make a reservation (which is required) by calling 215-794-4051. As for what you'll be dining on: You can scope out the menu online (and yes, the Girls’ favorite dessert is involved).

arrow
Pop Culture
Cheerleaders and Chicken Suits: Funko is Releasing Several Special Edition Deadpool POPs!

Marvel’s “Merc With a Mouth” is not only getting a sequel—he’s also getting some new swag. Deadpool, the sardonic superhero/villain in red spandex, will soon be immortalized in a new line of special edition Funko POP! vinyl toys.

In keeping with the franchise's eccentric sense of humor, there will be several outlandish outfits to choose from, each one sold exclusively by a different retailer. Among the outfit options Funko lovers will find are a mermaid get-up (complete with starfish bra) at Target; a cheerleader uniform for BoxLunch; a king’s robe and crown at FYE; and a chicken suit for Amazon shoppers. There’s even one of Deadpool holding a chimichanga while wearing ninja gear for 7-Eleven.

These parody dolls seem to be keeping in character with the Deadpool films, which themselves are parodies of the superhero genre. The title character, played by Ryan Reynolds, often breaks the fourth wall in order to poke fun at both DC and Marvel. (The filmmakers also famously signed off on spending $10,000 for a quick shot of the unlikely superhero wearing a tank top with Golden Girl Bea Arthur's face on it.)

The figures will be out this summer following the release of Deadpool 2 on May 18, 2018. Funko also recently released its royal family line of POP! dolls, depicting Britain’s longest-reigning monarch, Elizabeth II, and her kin.

SECTIONS

arrow
LIVE SMARTER