CLOSE
iStock
iStock

If You Can Solve This Math Puzzle, You Might Be a Genius

iStock
iStock

by Reader's Digest Editors

Do you think of yourself as a secret mathematician? This math brainteaser has even the biggest number nerds scratching their heads.

People’s Daily, China tweeted out this math puzzle in which each picture represents a number.

These algebra problems might seem easy at first glance, but hold on. People’s Daily was nice enough to give away the answer before you began. If you didn’t get 16, you did something wrong. Take a closer look at the pictures—you probably missed a few key details.

Still stumped? We’ll walk you through it. For the sake of the explanation, we’ll call the shoes S, the cat C, and the whistle W.

The first equation sets up the whole math puzzle. Three pairs of shoes added together equal thirty. S + S + S = 30, so divide 30 by three. Each pair of sneakers represents the number 10. Easy enough.

 
See Also...

The Town Located at the Center of North America Has the Absolute Perfect Name
*
Take a Sneak Peek Inside Largest Starbucks Store in the World
*
Why Airlines Don't Tell You How Long Flights Really Are
 

Now the second equation is clearer. Sub the shoes out for a 10, and you’ll find out 10 + C + C = 20. Subtract 10 from each side, so C + C = 10. Each cat must represent the number 5.

Look closely at the next equation before you jump into it. In the third equation, there are two whistles in each line, but the final one only has one whistle. So 5 + 2W + 2W = 13. If 4W = 8, then each whistle represents the number 2.

OK, so that clears up a bit of the next equation—until you plug the numbers in. Sub S + C x W for 10 + 5 x 2. Remember your order of operations? Multiply first, then add. So 10 + 10 = 20. What went wrong?

The key is in the cat’s clothes. In the second and third equations, the cat has a whistle around its neck—but not in the last one.

No need to go back and redo all your hard work. Just change the last equation to S + (C – W) x W. Now plug the numbers in: 10 + (5 – 2) x 2. Work your way through it. The equation goes to 10 + (3) x 2, then 10 + 6. Finally, you get 16—problem solved!

nextArticle.image_alt|e
Pop Chart Lab
arrow
infographics
Every Emoji Ever, Arranged by Color
Pop Chart Lab
Pop Chart Lab

What lies at the end of the emoji rainbow? It's not a pot of gold, but rather an exclamation point—a fitting way to round out the Every Emoji Ever print created by the design experts over at Pop Chart Lab.

As the name suggests, every emoji that's currently used in version 10.0.0 of Unicode is represented, which, if you're keeping track, is nearly 2400.

Each emoji was painstakingly hand-illustrated and arranged chromatically, starting with yellow and ending in white. Unicode was most recently updated last summer, with 56 emojis added to the family. Some of the newest members of the emoji clan include a mermaid, a couple of dinosaurs, a UFO, and a Chinese takeout box. However, the most popular emoji last year was the "despairing crying face." Make of that what you will.

Past posters from Pop Chart Lab have depicted the instruments played in every Beatles song, every bird species in North America, and magical objects of the wizarding world. The price of the Every Emoji Ever poster starts at $29, and if you're interested, the piece can be purchased here.

nextArticle.image_alt|e
Getty Images
arrow
fun
A Brief History of the High Five
Getty Images
Getty Images

Since 2002, the third Thursday of April is recognized as National High Five Day—a 24-hour period for giving familiars and strangers alike as many high fives as humanly possible. A few University of Virginia students invented the day, which has since evolved into a “High 5-A-Thon” that raises money each year for for a good cause. (For 2018, it's CoachArt, a nonprofit organization that engages kids impacted by chronic illness in arts and athletics.) Here are a few more facts about the history of the hand gesture to get you in the high-fiving spirit.

UP HIGH

That may sound like a lot of celebration for a simple hand gesture, but the truth is, the act of reaching your arm up over your head and slapping the elevated palm and five fingers of another person has revolutionized the way Americans (and many all over world) cheer for everything from personal achievements to miraculous game-winning plays in the sports world. Psychological studies on touch and human contact have found that gestures like the high five enhance bonding among sports teammates, which in turn has a winning effect on the whole team. Put 'er there!

DOWN LOW

There is some dispute about who actually invented the high five. Some claim the gesture was invented by Los Angeles Dodgers outfielder Glenn Burke when he spontaneously high-fived fellow outfielder Dusty Baker after a home run during a game in 1977. Others claim the 1978-79 Louisville basketball team started it on the court. Since no one could definitively pinpoint the exact origin, National High Five Day co-founder Conor Lastowka made up a story about Murray State basketballer Lamont Sleets inventing it in the late '70s/early '80s, inspired by his father's Vietnam unit, “The Fives.”

Regardless of which high-five origin story is more accurate, there is little question of its roots. The high five evolved from its sister-in-slappage, the low five. The gesture, also known as “slapping skin,” was made popular in the jazz age by the likes of Al Jolson, Cab Calloway and the Andrews Sisters.

GIMME FIVE

As the high five has evolved over the past few decades, variations have developed and become popular in and of themselves. Here are five popular styles:

The Baby Five
Before most babies learn to walk or talk, they learn to high five. Baby hands are much smaller than adult hands, so grownups have to either use one finger, scrunch their fingers together or flat-out palm it.

The Air Five
Also known as the "wi-five" in the more recent technology age, this one is achieved just like a regular high five, minus the hand-to-hand contact. Its great for germaphobes and long distance celebrations.

The Double High Five
Also known as a “high ten,” it is characterized by using both hands simultaneously to high five.

The Fist Bump
It's a trendy offshoot of the high five that made headlines thanks to a public display by the U.S. President and First Lady. Instead of palm slapping, it involves contact between the knuckles of two balled fists. In some cases, the fist bump can be “exploding,” by which the bump is followed by a fanning out of all involved fingers.

The Self High Five
If something awesome happens and there's no one else around, the self high five may be appropriate. It happens when one person raises one hand and brings the other hand up to meet it, high-five style. Pro-wrestler Diamond Dallas Page made the move famous in his appearances at WCW matches.

YOU'RE TOO SLOW!

Don't fall for that old joke. The key to a solid high five is threefold. Always watch for the elbow of your high-fiving mate to ensure accuracy; never leave a buddy hanging; and always have hand sanitizer on you. Have a Happy High Five Day!

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios