upworthy

Learning

Education

In the early 80s, there was one SAT question that was literally impossible to answer

Everyone got it wrong and it wasn't their fault.

Photo by Nathan Dumlao on Unsplash

Teenager is baffled.

As if the SAT didn't already have a less-than-stellar reputation in terms of racial bias and the possible inability to truly measure a student's cognitive abilities, now a story about an expensive blunder is once again making the rounds on social media. Back in 1982, one math question on the test was completely impossible to answer on the multiple-choice Scantron. How was that possible? Because the correct answer hadn't even been listed.

Pencil, SAT test, Scantron, testing, SATsClassic SAT test. Photo by Nguyen Dang Hoang Nhu on Unsplash

Here was the question: Picture two circles, a large one marked B and a smaller one next to it with an arrow, marked A. "In the figure above, the radius of Circle A is 1/3 the radius of Circle B. Starting from the position shown in the figure, Circle A rolls around Circle B. At the end of how many revolutions of Circle A will the center of the circle first reach its starting point?" Is it A, 3/2; B, three; C, six; D, 9/2; or E, nine?

On the Veritasium YouTube page, they explain that if you were to look at the problem logically, you'd conclude the answer was B, three. Because the circumference of a circle is 2πr, and the radius of Circle B is three times that of Circle A, "logically it should take three full rotations of Circle A to roll around." However, that answer is wrong.

- YouTubewww.youtube.com

In Jack Murtagh's piece "The SAT Problem that Everyone Got Wrong" for Scientific American, he conveys it all came down to the Coin Rotation Paradox (take note of this if you want to sound super intelligent on your next date or job interview).

You can try this yourself. Murtagh writes, "Here's how the paradox works: Place two quarters flat on a table so that they are touching. Holding one coin stationary on the table, roll the other quarter around it, keeping edge contact between the two without slipping. When the moving quarter returns to its starting location, how many full rotations has it made?"

Again, most test takers assumed that the answer was three. But "in fact, Circle A makes four rotations on its trip—again, exactly one more rotation than intuition expects. The paradox was so far from the test writers’ awareness that four wasn’t offered as an option among the possible answers, so even the most astute students were forced to submit a wrong response."

Why in fact was this the case? On the Scientific American YouTube page, it's explained again: "If you replace the larger circle with a straight line of the same length, then the smaller circle would indeed make three rotations. Somehow the circular path creates an extra rotation. And to see why, just imagine rotating a circle around a single point. There are two sources of rotation here. One from rolling along a path—and the longer the path is, the more rotations. And another from revolving around an object, which creates one extra rotation, no matter its size."

- YouTubewww.youtube.com

Okay, one more try. Here, it's relayed in terms of actual astrophysics: "This general principle extends far beyond a mathematical fun fact. In fact, it's essential in astronomy for accurate timekeeping. When we count 365 days going by in a year—365.24, to be precise—we say we're just counting how many rotations the Earth makes in one orbit around the Sun. But it's not that simple. All this counting is done from the perspective of you on Earth. To an external observer, they'll see the Earth do one extra rotation to account for its circular path around the Sun. So while we count 365.24 days in a year, they count 366.24 days in a year."

What might be equally interesting is that out of 300,000 SAT test-takers who got that question at the time, only three wrote in to the College Board to challenge the answer. Ultimately, they had to fix the test, which cost them over $100,000. (In 1982, that's at least ten Happy Meals.)

The comment section on YouTube was buzzing.

gif, wrong, reaction, reaction gif, math problemYoure Wrong John C Mcginley GIFGiphy

This person suggests following your gut, even if that does mean challenging a professor or other authority figure: "In college, I took a poetry class and once had an answer marked wrong on a test. Confident in my response, I reached out to the poet themselves, who affirmed I was right and even communicated this to my professor. Despite not being a fan of poetry, that moment made me quite proud!"

Another person commented on the reasoning behind the paradox itself: "That part about the circle rotating around the triangle was mind-blowing. You instantly understand why it's not the same if the circle rolls on a flat line or rolls on a curved line."

And for this person, it brought peace of mind: "This was the one SAT I took, and I remember the question that didn't have a correct answer, and it wasn't until today that I understood the right answer. I can die happy now."

From Your Site Articles
standardized tests
Learning

In two sentences, finance guy crushes the idea of buying a new car. But people disagree.

Here's why people are still doing it.

via Canva/Photos

A woman gets the keys to her new car.

There are many reasons to be squeamish about spending money in today’s economy. Interest rates are high, trade wars may drive inflation, and financial experts say we may be headed for a recession. That comes after the post-COVID period, when the process of everyday necessities, such as rent and groceries, went sky-high.

There’s a lot of economic uncertainty out there, but that won’t stop some of us from needing a car. And, of course, those are getting more expensive, too. The average car cost $49,740 in January, nearly an all-time high. Part of that is inflation, but it’s also because Americans love buying nice cars, and more are choosing luxury models. So now, to purchase a new car at $49,740, with zero dollars down and a 5-year loan, would cost over $950 a month. That’s a lot of money for something that will only decrease in value.

Real estate expert and author of “Retire FIlthy Rich,“ Ravi Sharma, wasn’t shy about sharing his thoughts about buying a new car on TikTok. The post received over 1.2 million views.

"Controversial topic: That $50,000 car loan that you finally paid off after 5 years cost you $62,000 (due to interest). That car is now worth $20,000 due to depreciation. Losing $42,000 in 5 years would be seen as a bad investment, yet people are still buying new cars. Thoughts?"

@personalfinancewithravi

Controversial Topic - What’s your thoughts about this? 🤔 #personalfinancewithravi

Is it financially smart to buy a new car?

Sharma’s logic is hard to argue with. A car is a depreciating asset that will lose its value over time. In fact, according to Kelly Blue Book, the average new car loses 20% of its value after the first year. That number grows to over 60% after five years. So, why not buy a car that’s five years old, costs less money, and is significantly cheaper to insure?

Strangely, most people in the comments pushed back against Sharma’s logic. "You forgot to factor in the benefit of owning that vehicle and the pleasure of driving it. For most, it's priceless. Not everything in life is about making money," Patty wrote. "I have 3 bad investments and loving them. We only live once. Enjoy,” Rich added. Others noted that even though the car's value goes down, you got use out of the vehicle so it's not a total loss.

new car, finance, ravi sharmaA woman inspects her new car. via Canva/Photos

There were a few people who agreed with Sharma. "Yes! Car payments are one of the top wealth killers. I have always bought used and paid cash,” a commenter wrote. "Amen. I’ve never purchased a brand-new vehicle. If you want to be a millionaire, don’t live like one,” another added. "Just driving the new car off the lot depreciates it by 20-25%. Buying pre-owned, someone else took that depreciation. Don't believe me? Buy a $50k new car then try to sell it tomorrow,” a commenter wrote.

Many people pushed back against Sharma because buying a new vehicle gives them joy. But the real question is, how long does that last before it just becomes your everyday car and no longer has the wow factor it had when you drove it off the lot? Further, going back to our car that cost $49,740 and about $950 a month, what if you bought a car for half the price and invested the $475 a month of the payment in a sensible mutual fund? After 5 years at 6% of growth, that would amount to over $32,000.

new car, finance, ravi sharmaA woman gets the keys to her new car.via Canva/Photos

With the constantly rising cost of living, it’s good to consider what it really means to make a big purchase and whether the joy of something new is worth the loss that comes with spending versus investing. Ultimately, the decision comes down to one’s values and financial priorities. Is short-term satisfaction worth the long-term cost when opting for a used car means more financial freedom tomorrow?

From Your Site Articles
economics
Education

Former Secret Service agent reveals 'spy trick' for getting someone to do exactly what you want

It's so subtle, they'll never catch on to what you're doing.

via Matthew Haddix/Flickr and Mart Production/Pexels

Former Secret Service Special agent Evy Poumpouras speaks at a Ted Talk.

In a revealing interview with Steven Bartlett on his “Dairy of a CEO” podcast, former Secret Service Special Agent Evy Poumpouras shared how to get people to do what you want them to do. The key, according to Poumpouras, is to understand what motivates them. Once you know the psychological framework behind what makes them tick, you can persuade them to behave as you like.

Poumpouras is the co-host of Bravo TV’s “Spy Games” competition series and author of “Becoming Bulletproof: Protect Yourself, Read People, Influence Situations, Live Fearlessly.” She served in the Secret Service’s Presidential Protective Division for President Barack Obama and First Lady Michelle Obama and protected George W. Bush, Bill Clinton and George H.W. Bush.

Poumpouras says that to get a “good read” on someone, it’s essential to listen.

Former U.S. Secret Service Special Agent Evy Poumpouras shares how to get someone to do what you want

@steven

Former U.S. Secret Service Special Agent Evy Poumpouras shares how to get someone to do what you want 👀 #podcast #podcastclips #stevenbartlett #diaryofaceo #specialagent #secretservice #security #evypoumpouras

The biggest mistake people make is they talk a lot,” Poumpouras said in the video clip. “Steven, if I'm doing all the talking and you're doing all the listening, you're learning everything about me. You're learning about what I care about, my values, my belief systems, getting a good read on me and I'm learning nothing about you.”

The former Secret Service Agent says that you should listen to determine the subject's motivational mindset. Are they motivated by money, sex, admiration, status, freedom, relationships, or safety?

“Everybody's motivated by something different. But I have to hear you and pay attention to you to understand what that is. Everybody's purpose is different,” she continued. “If you give people enough space, they will reveal themselves to you.”

It’s also a wonderful tactic because your subject will have no idea they are part of a manipulation because they are the ones doing the talking. It’s nearly impossible to give yourself away when you’re sitting in silence.

Understanding what motivates people is essential when protecting the safety of the nation’s most important assets and dealing with shady, dangerous people. However, it can also benefit the layperson by giving us a framework to understand people better. Knowing what motivates someone is very important, whether you’re on a date, in a business deal, or in a leadership role at work.

It’s also very important when raising children or training an animal.

Understanding your personal motivators is also essential for making the best choices in life. It helps us determine which actions will be genuinely beneficial. It’s also a great way to ensure that we are involved with people, organizations, and activities for the right reasons.

Productivity consultant Ashley Janssen says the key to understanding your motives is knowing your values.

"When you know what you value, you can identify how an activity or goal will support and foster those values," Janssen writes. "When you decide to try something, consider whether it’s what you think you should want to do or what someone else has said you should do. Those conditions are often not enough to sustain a behavior or activity. It’s hard to keep moving forward on something that you don’t really care about or are not invested in."


This article originally appeared last year.

From Your Site Articles
psychology
Education

5 lessons we can take away from the Delta flight that crashed upside down on the runway

1) Always obey seat belt instructions.

Photo credit: YYZBrennan

A Delta flight from Minneapolis flipped over and caught fire upon landing in Toronto.

Flying has often been touted as one of the safest modes of transportation, but after a rash of aviation accidents in February of 2025, people are starting to have questions. What the heck is happening in the friendly skies? Why is there a sudden uptick in plane crashes? Is flying still safe?

One of the weirdest aviation incidents we've seen is the Delta flight that flipped upside down upon landing in Toronto on February 17, knocking off a wing and catching fire as it skidded to a stop on the tarmac. The 76 passengers on the commuter plane found themselves hanging upside down in the cabin as flight attendants raced to get everyone out of the plan quickly and safely. Miraculously, no one was killed, and though 21 injured passengers were initially transported to the hospital, 19 have been released as of February 19.

The thought of having your airplane do a 180-degree roll on the runway and having to exit a burning aircraft from a bat-like position is sheer nightmare fuel, but there are some important lessons we can all learn from how this incident played out.

1. Always obey seat belt instructions—"low and tight across your lap"

If you fly with any regularity at all, chances are you zone out during the pre-takeoff safety instructions, but this accident definitely has us all at least thinking about our seat belt compliance. Imagine how easy it would be to slip out of the seat belt hanging upside down if it weren't buckled low and tight.

There's a reason the seat belt sign exists. If footage of extreme turbulence isn't enough to rattle you into always staying buckled when the light is on, this crash likely will.

2. Respect your flight attendants

Flight attendants sometimes have to deal with difficult or rude passengers, which is unfortunate, especially since those same passengers rely on flight attendants to do their jobs in an emergency to ensure their safety. Flight attendants don't get to freak out when a plane crashes—they have to tap right into their emergency evacuation training.

But in this case, there was no specific training for this specific scenario because who would imagine it ever happening? But those flight attendants were able to improvise and get the passengers on board out of their upside down positions, out the exits and onto the tarmac within seconds of the crash happening. This is a good reminder that even though flying is usually smooth and without incident, flight attendants are primarily there for our safety, not servers there at our beck and call.

3. Regulations in aircraft design help keep us safe

One of the reasons this crash went the way it did is because of the way the plane was designed and made. From the way the wing broke off without tearing apart the fuselage (the body of the plane) to the way the seats remained in tact and firmly planted despite being upside down with people in them, the aviation engineers behind the building of this aircraft—as well as the regulations in place that require more safety features—deserve some kudos.

“Everything that could go wrong went wrong, yet 80 people survived the accident,” said David Soucie, a CNN safety analyst and former FAA safety inspector who credited better plane design, improved safety and stronger, more secure seats for the survival rate.

"Even the design of the seat back or the tray table is all part of how we consider making that survivable space," Graham Braithwaite, professor of safety and accident investigation at the UK's Cranfield University, told the BBC. "And the seatbelt that people have is so important - that is the ultimate thing that stops people being thrown around the cabin like this."

4. People are pretty awesome, actually

Reports from people who were on the flight indicate that the passengers helped one another out and were generally awesome in an incredibly harrowing situation.

One man shared that he and the woman sitting next to him, who hadn't spoken to each other the entire flight, gave one another a long hug after getting out of their seats. "It was nice to see people working together, as in like no one held anyone back from getting off the plane or getting out of their seat, or whatever," he said. "No one was like, 'I need to be first!'"

Working together with the crew to evacuate smoothly may have saved lives, as he reported there was an explosion a few minutes after everyone got off the plane. Phew.

"The most powerful part of today was, there was just people. No countries, no nothing," another passenger said. "There was just people together helping each other." Beautiful.

5. Flying is still dramatically safer than driving

Even with the wave of plane incidents we've seen included, flying is still statistically safer than driving in a car. People are understandably nervous about flying right now, but that's the impact of mass media coverage. If we saw news stories and headlines about every car accident in the country every day, we'd be freaking out about driving cars, but we don't see those. Accidents happen in aviation, but usually only the major commercial plane incidents make national or international news.

If we look just as the numbers, January of 2025 was actually a record low month of airplane accidents nationwide. Not to downplay what's been happening in February, but we've really become accustomed to extreme safety when it comes to flying. The past 15 years have seen the lowest airplane fatalities than any other 15-year period ever, so we should probably wait to freak out too much over the seemingly anomalous accident rate of the past two weeks.

At least that's what I'm telling myself before I hop on my next flight.

From Your Site Articles
air travel
Trending Stories