## A pilot and an architect try answering the Google job interview brain teaser

• We wanted to see how two experts in completely different fields would answer one such question.
• Pilot Anna Battison and architect Samantha Josephat both answered a brain teaser Google used to ask job candidates: How many golf balls fit into a Boeing 747?
• With their different professional backgrounds, the two experts approached the question in very different ways.
• Visit Business Insider’s homepage for more stories.

Following is a transcript of the video.

Anna Battison: Well, I hope that’s accurate. I feel like I should maybe ask somebody.

Samantha Josaphat: Um, wish me luck.

Battison: So, how many golf balls can you fit in a Boeing 747? I… I have no idea.

Josaphat: How many tennis balls? Oh, golf…wow. Wow. My first step is to dimension the size of a golf ball, which I actually don’t know.

Battison: A golf ball is, I don’t know…

Josaphat: I’ve never played golf before.

Battison: If you play tennis, a little bit smaller than a tennis ball. Josaphat: I’m gonna predict that a golf ball is 4 inches by 4 inches in diameter.

Battison: And a headrest is probably, I don’t know. Here’s my head. So let’s say it’s that big and maybe that thick. And now I’m just trying to break down the seat to figure out how many golf balls are in it. So, in this headrest, there are about 15. I’m gonna say that there are three rows of three headrests that can fit in the back portion of it. And then I’m gonna say there’s two rows of three for the bottom part. Then that gives us three, six, nine on the top, six on the bottom. 15 times 15 golf balls in each headrest. There are 15 headrests in the seat. That gives us 225 golf balls per seat.

Josaphat: I’m now attempting to draw a plane. I’m such an architect. It’s like, I gotta get it right. Oh, gosh! I’m sorry. That looks horrible. Can I just line up my wings?

Battison: This is very bad. So, you have the cabin, which is like, X1, X2 is, like, where the passenger goes with all the seats. Those are what the seats are. And then X3, which is, like, the undercarriage, which might be down here, and, you know, just where all the luggage goes.

Josaphat: When I first think about the plane and plan, what is a variable that I can replicate numerous times? And that’s the seat.

Battison: In a 747, primarily have two seats here, two seats here, an aisle, an aisle, and three seats in the middle. So that’s seven seats across in each row.

Josaphat: I will assume a Boeing 747 has about 80 rows.

Battison: So if there are 366 seats, so 366 seats in a Boeing 747, that means that 366 divided by seven would be about 52 rows.

Josaphat: Now, if I were to say a typical chair for a person is about 18 inches wide and a Boeing 747 has three aisles of seating with potentially four seats in the middle, three seats on either end, how many seats are in just one row?

Battison: I’m gonna add two seats per row because there’s an aisle here where I can add a seat, hypothetically. So if I’m adding two seats per row, that would give me 104 extra seats that I could fit in for that first layer across the bottom. There’s 470 seats on the bottom layer times 225. That gives me 105,750 golf balls.

Josaphat: So we have, six and four is 10. So we have 10 times 18. That gives us 180 inches. Then we multiply that by 80 rows. That’s 14,400 inches. That’d give me 1,200 feet. So now we would have to incorporate circulation.

Battison: Now, you gotta think about, those golf balls are really small. I’ve got so many gaps in between each seat.

Josaphat: So, if I were to relate circulation to an airplane, that would mean the aisles that go from the front and the back of the plane, the space in between the seats so that everyone can get to their seat comfortably. Battison: I’m gonna seriously ballpark this. So, across, I’ve got seven seats. Let’s say there are seven gaps where 100 golf balls can fit. That’s seven gaps in each row. So seven times 52 rows is 364. So 364 times, let’s say in each gap, 100 golf balls can fit, 36,400.

Josaphat: And, like, a typical building, in New York City’s Standard of Quality Housing, you need about 30% of circulation in a space. So what’s 30% of 1,200 feet? That’s 360 feet. That’s 360…square feet. I just realized it’s not just feet. 1,200 square feet plus 360 gives us 1,560 square feet. So that includes seats and circulation.

Battison: So, now I’m gonna picture how many layers of seats can I stack on top of each other in that gap in the cabin. I’m gonna say maybe three rows, just ’cause the seats are high. So then I’m gonna do that number times three, 317,250 golf balls. That’s how many golf balls I have in three layers of seats. And that comes out as being 353,650.

Josaphat: Now we have to think about the cockpit, where the pilot is, as well as areas for meal prep and the bathrooms.

Battison: X2 is very big, right? It’s, like, 52 rows plus the space on top. So I’m gonna say there’s, you know, gotta be at least 10 that’ll fit in there. Now, maybe that’s a little bit overestimating, but I think I underestimated for the amount of golf balls anyway. So let’s just go with that.

Josaphat: So, I’m just gonna estimate 40%. ‘Cause typically in a building, you have to think about, 40% of the space goes to infrastructure, like mechanical systems and plumbing.

Battison: So if there are 353,650 golf balls that fit into the cabin, there would be 10 that fit in there, so that number divided by 10. That’s gonna be 35,365.

Josaphat: What’s 40% of 1,560 square feet? So now we’ll do 624 plus 1,560, and that’ll get us 2,184. So now we have the floor plan covered. And now we have to think about it in volume.

Battison: The X3 is what we have left.

Josaphat: Typical height in an apartment in New York could be around 8 to 10 feet high. And then the height of the carry-on luggage. So we’ll say 11 feet head clearance, and then we’ll add an additional two feet for the material of the plane. And so that’s 13 feet height.

Battison: I don’t actually know exactly how big a 747 is, but I would imagine very, very big.

Josaphat: Now, if we have to consider the space below where the baggage claim is, typically, someone can actually walk in that space to grab luggage.

Battison: I would say that it’s roughly the same size as the cabin or maybe even bigger.

Josaphat: And so I will just double that height and make that 26 feet. Now I will multiply 26 feet by 2,184 square feet.

Battison: The grand total is now 35,365 plus 353,650 plus 353 again, 650, equals 742,665. So that’s our grand total for a 747 that does not actually have the 366 seats.

Josaphat: So, my last step would be to divide the total cubic feet of the plane by the cubic feet that I’ve figured out for the golf ball.

Battison: But if we have an airliner, we do have those seats that can’t hold the golf balls.

Josaphat: 56,784 cubic feet divided by 12 cubic feet. That total answer would be 4,732 golf balls.

Battison: If it has 366 seats, 366 seats times however many golf balls can fit into each seat, we said was 225. So 366 times 225 would give us 82,350.

Josaphat: That really does not feel real. I’m not comfortable with that answer.

Battison: So I’m going to do this number minus this number to get our grand total for an airline 747. Gives us 660,315 golf balls.

Josaphat: Oh, I know what the problem is. I did 12 cubic feet, not 12 cubic inches. So there’s actually another step. That would be multiplying by 12. Oh, that’s funny. Which would give me 56,784 golf balls. Final answer.

Battison: I have a gut feeling that that’s way too little.

Josaphat: It may be a little bit low still. I mean, I’m gonna have to trust the math at this point.

Battison: I thought I would come out to a number that was maybe a million or so. I think I told you, a headrest is about, like, this big.

Josaphat: So if I were to go back, I’d probably tweak the size of the golf ball.

Battison: I think far more than 15 golf balls can fit into there. Maybe more along the range of 25 or 30 golf balls. In aviation, they always want you to refer back to, you know, facts. You’re always supposed to follow your checklist in an emergency. You’re supposed to rely on your instruments.

Josaphat: It did bring back the inner third grade in me, where it’s like, oh, you gotta stay up all night and figure out this math problem. Battison: Do you have an actual answer?

Alex Appolonia: Well, not exactly. We found a lot of different answers to this brain teaser. But the whole point of these questions is to show how people think. Google no longer asks these brain teasers, because they don’t predict how well someone would do at a job, but we wanted to have a little fun with it. Feel free to let us know in the comments below more brain teasers you would like to see solved, and make sure you subscribe to our channel, so you don’t miss it.

EDITOR’S NOTE: This video was originally published in October 2020.

## Elon Musk’s Neuralink scientists are not the first to get a monkey to control a computer with its mind

• Elon Musk’s Neuralink showed off its technology allowing a monkey to play video games with its mind.
• Scientists have been able to get monkeys to control computer cursors via neural interfaces since 2002.
• It’s an important test of Neuralink’s technology, but not a revolutionary piece of science.
• See more stories on Insider’s business page.

This week, Neuralink, a company founded by Elon Musk that specialises in neural interface technology, unveiled a fairly astonishing example of its work.

In a video released Thursday, the company showed off how far its come testing its technology on primates. In the video, a macaque monkey named Pager, which Neuralink claims has had a chip implanted in his brain for six weeks, is able to play video games like Pong purely via the chip. Playing the games correctly meant Pager was rewarded with a sip of banana smoothie.

This is, objectively, pretty amazing. As Musk put it in an excited tweet on Thursday: “A monkey is literally playing a video game telepathically using a brain chip!!”

Perhaps even more amazing: monkeys have been playing video games with their minds for almost 20 years.

“Brain-control of computer cursors by monkeys is not new,” Professor Andrew Jackson of the University of Newcastle told Insider, adding that the first comparable demonstrations of technology like Neuralink’s took place in 2002.

A group of researchers in 2002 were able to show they could get a monkey to move a cursor on a computer screen at will, noting at the time that the technology could be used to help paralyzed people control screens in a similar way.

Jackson added the idea behind the technology dates back as far as the 1960s. In 1969, a researcher called Eberhard Fetz connected a needle on a meter to a single neuron in a monkey’s brain, and was able to train the monkey to move that needle using only its brain activity.

Neuralink, which was founded in 2016, is developing a microchip, which theoretically, would be implanted in a person’s skull, from which wires would fan out into their brain. These wires would be able to record brain activity, as well as stimulate areas of the brain.

The idea is that these chips could help study and treat neurological diseases and conditions in the near term. In the long term, Musk says they form part of his ideal of a “symbiosis” between human consciousness and AI (although experts have frequently expressed skepticism about this part).

## Musk has been hyping up the monkey for years – but neuroscientists haven’t been that impressed

Musk first gave the world a hint about Neuralink’s tests on monkeys during a streamed presentation of the company’s designs in 2019.

“A monkey has been able to control a computer with its brain, just FYI,” he said, appearing to take Neuralink president Max Kodak by surprise with the announcement. “The monkey’s going to come out of the bag,” Musk joked.

Andrew Hires, an assistant professor of neurobiology at the University of California, told Insider in 2019 that he was not surprised Neuralink had been able to achieve that result – and accurately predicted the kind of telepathic monkey computer-usage which Neuralink showed off in its video on Friday.

“The monkey is not surfing the internet. The monkey is probably moving a cursor to move a little ball to try to match a target,” Hires said. This pretty well exactly matches one of the games Pager was shown playing in the video released Thursday.

Musk started to hype up the monkey again earlier this year. “We’ve already got a monkey with a wireless implant in their skull … who can play video games using his mind,” he said during an interview on Clubhouse on January 31.

Musk is a canny marketer, and he’s very familiar with using his own peculiar brand of fame to merchandise and advertise his companies. It’s worth noting that at the end of the video with a call for people to apply for jobs at Neuralink – making for an ingenious recruitment strategy.

## Neuralink is still doing new things, and the monkey is important

While neuroscientists have said the underlying science of getting a monkey to play video games with its mind is not revolutionary, they have praised the engineering of Neuralink’s wireless chip.

Speaking to Insider in September 2020 (following a presentation in which Neuralink showed off its technology working after being implanted in the brain of a pig) Professor Jackson said the development of any neural interface technology that doesn’t require wires to protrude out of the skin is a good thing, as it reduces the risk of infection.

“Just from a welfare aspect for the animals, I think if you can do experiments with something that doesn’t involve wires coming through the skin, that’s going to improve the welfare of animals,” he said, adding that further down the road it could have benefits for humans as well.

Responding to the video released on Thursday of Pager the monkey, Jackson said while it’s not earth-shattering, it is an important proof of concept.

“I certainly do not mean to criticise them for demonstrating something that has been done before. It is a sensible way to validate any new technology. If you invent a new telescope, it makes sense to first point it where you know what you will see. So they are following a very sensible route to validate their device,” Jackson said.

Rylie Green, a bioengineering researcher at Imperial College London, told Insider: “The best thing I can see from that video is that the macaque is freely moving. There’s also no visible package connected to it. I would say that is definitely progress – not super innovative but a nice positive step forward.”

## How giving birth changes your brain

• A new mother experiences many changes after giving birth. Some of the biggest happen in her brain.
• When she first sees her newborn, core regions of her brain’s reward network kick in, giving her an instant connection to her baby.
• Fathers also experience changes their brains when they spend quality time with their babies.
• Visit Business Insider’s homepage for more stories.

Following is a transcript of the video.

A woman’s uterus grows to over 500 times its normal size during pregnancy. But not all changes are visible. In fact, some of the biggest changes happen in her brain.

When a mother sees her newborn for the first time, it’s love at first sight, literally. That’s because once she gives birth, core regions of her brain’s reward network kick in. They signal the release of feel-good hormones like dopamine and oxytocin into her blood, which immediately triggers a strong connection of love and devotion to her newborn. In fact, studies show that recent mothers have similar levels of oxytocin as romantic couples who are newly in love.

And human moms aren’t alone here. Scientists discovered that rodents got a bigger kick of dopamine from feeding their pups than from receiving injections of cocaine. What’s more, brain scans reveal that a human mom has a similar experience when she sees her infant smiling.

But it’s a different story when her baby is crying. Those cries activate a network in the mom’s brain known as the emotion regulation network. It includes the prefrontal and cingulate control systems, which help control her emotions. And that’s important since it can be easy to lose your temper when you’re running on very little sleep and are distressed by the baby’s cries.

And while motherhood can be exhausting, new moms are actually more alert than normal thanks to their brain’s salience network. Scientists think giving birth activates this network to help a mother detect threats and protect her infant from harm, especially in dangerous situations when that network can help ramp up adrenaline.

But on a daily basis, Mom needs to understand her newborn’s needs. To accomplish that, she uses empathy, which comes from her brain’s social network. It involves the insular and amygdala, which researchers found became more active when moms looked at photos of their babies in distress compared to neutral photos.

But it’s not just the mom’s brain that changes. Research shows that a dad’s brain releases oxytocin when he interacts with his baby too. This is often accompanied by a surge of another hormone: prolactin. It’s often called the milk hormone because it triggers the production of breast milk, but men can produce it too, and researchers have found that dads who frequently played with their babies had higher prolactin levels in their blood than fathers who didn’t. They were also more responsive to their baby’s cries.

So in the end, having a child is a big change. Not just for your lifestyle, for your brain too.

EDITOR’S NOTE: This video was originally published in April 2019.

## What happens to your brain and body when you procrastinate too much

There’s a reason why people are such bad procrastinators. It’s easy: Procrastinating feels great. But it’s not so great for your brain since it pits two of your brain’s heavy hitters, your limbic system, and your prefrontal cortex into a literal head-to-head match.

Following is a transcript of the video.

Most of us have procrastinated at some point in our lives. But about one in every five of us are compulsive about it. Putting off tasks and chores nearly every chance they get.

They’re called chronic procrastinators. And it turns out, this behavior does a lot more damage than you might think.

We get it, doing work is hard.

But when you choose to watch TV over doing laundry or washing the dishes you’ve just launched an all-out battle in your brain.

On one side is your prefrontal cortex. That’s the part of your brain that sets long-term goals and regulates self-control. It’s telling you that those dishes aren’t going to clean themselves.

On the opposing side is your limbic system. It deals with pleasure, arousal, and reward.

And it’s telling you that washing dishes is no fun, and you’ll have a better time doing something else. So, procrastination essentially puts your brain in its happy place.

It feels good. That’s why you do it. But just because it feels good doesn’t necessarily mean it’s good for you.

For example, several studies have found that undergraduate college students who procrastinated had a lower GPA in the latter half of the semester compared to non-procrastinators.

They were also more likely to get sick, based on their healthcare visits.

Moreover, other studies have found that procrastinators report higher levels of guilt and anxiety when they choose to procrastinate in the first place.

And if you keep it up, researchers have found that chronic procrastination is linked to: low self-confidence, Low energy, And depression.

Overall, your quality of life will probably be worse, than if you just listened to your prefrontal cortex. And you may think that you just have a different workflow or that you perform better under pressure.

But, sorry to say, there are no studies to support any benefits of chronic procrastination. Bottom line: it’s unhealthy. But not all hope is lost.

In fact, researchers have conducted dozens of scientific studies in search for ways to help procrastinators. What they’ve found time and again is that how you think about tasks can make a huge difference in how likely you are to procrastinate on them.

Tasks like saving for retirement, for example, can be abstract: There’s no immediate deadline, so you can always start tomorrow. And it’s this mentality that can lead you to procrastinate.