Can you solve this?

Video transcript

[In this video the interviewer is outdoors in a park. At different times, he stops four different couples and one man on his own. He gives them the numbers 2-4-8 and asks them to work out his number rule. He asks them to propose three numbers of their own in a sequence that follows the rule and to tell him what his rule is. The video jumps around to show him asking all of the people the question before showing any of their responses.]

Interviewer: Name unknown

[A young man with a beard, blue shirt and jumper with sunglasses tucked into his shirt neck]

I’m gonna give you guys three numbers. A three number sequence and I have a rule in mind that these three numbers obey and I want you to try to figure out what that rule is.

But the way that you can get information is by proposing your own set of three numbers, to which will say yes that follows my rule or no it doesn’t follow my rule. And then you can propose what you think the rule is.

Is that fair?

Couple 1:

[A young man in a dark corduroy coat and a young woman with a white beanie and leopard print scarf.]

Yep

Interviewer:

Okay, so here are the three numbers: 2, 4, 8.

Couple 1:

Woman: [repeats] 2, 4, 8

Interviewer:

You don’t need to continue the sequence, you can propose a totally different sequence, whatever you want to propose and I will simply say yes or no that follows my rule.

Man:

[A middle-aged man in a baseball cap and denim jacket.]

2, 4, 8 … 16, 32

Couple 2:

[A young man in a grey sweatshirt and padded vest with a young woman with long brown hair, wearing a parka and a baseball cap with NY on it.]

16, 32 and 64

Interviewer:

Those also follow my rule.

Couple 2:

Okay

Interviewer:

What’s the rule?

Couple 1:

Ah, multiply by 2?

Interviewer:

That is not my rule.

Couple 2:

What?

Interviewer:

That’s not my rule. But you’re allowed, if you want, propose three other numbers.

Couple 1:

3, 6, 12

Couple 3:

[An older man wearing a baseball cap, glasses and a leather jacket with an older woman in a pink parka and white framed sunglasses.]

3, 6, 12 .. ah ha

Interviewer:

3, 6, 12 follows my rule

Couple 3:

10, 20, 40

Couple 1:

10, 20, 40

Interviewer:

That follows the rule

Couple 1:

I'm also multiplying by 2

Interviewer:

I know, I know what you are doing and yes it follows my rule, but no it’s not my rule

Man:

5, 10

Couple 1:

10, and 20

Interviewer:

Follows my rule

Man:

100

Couple 3:

200, 400

Interviewer:

Follows my rule

Man:

500, 1000, 2000

Interviewer:

Follows my rule

Man:

Want me to keep going?

Couple 1:

Do I just keep going … you going to tell me your rule …? [laughter]

Man:

Am I doing it the wrong way, am I approaching this the wrong way?

Interviewer:

You’re totally fine but you are approaching it the way most people approach it.

Think strategically about this, you want information, I have information, the point of the three numbers, right is to allow you to figure out what the rule is.

Couple 2:

Okay

Man:

Okay, I am going to give you the numbers that I don’t think fits the sequence and then see what you say. So I’ll say 2, 4, 7

Interviewer:

Fits my rule

Man:

So whatever I propose is right?

Couple 2:

So is your rule like, you can propose any number?

Couple 1:

So the rule’s anything we say is yes?

Interviewer:

No

Man:

Dammit

Interviewer:

But you are on the right track now. Hit me with three numbers.

Couple 1 - woman:

3, 6, 9

Interviewer:

Follows my rule

Couple 1 – man:

Oh, that didn’t follow my rule

Interviewer:

This is good right?

Couple 2:

5, 10, 15

Interviewer:

That follows my rule

Couple 2:

What? Oh. Really?

Interviewer:

Yeah

Couple 3:

I don’t believe this. [laughter]

Couple 2:

1, 2, 3 ?

Couple 1:

1, 2, 3?

Interviewer:

Follows the rule

Couple 2:

What about 7, 8, 9?

Interviewer:

Follows the [laughter], yes that follows the rule

Man:

8, 16, 39

Interviewer:

Fits the rule

Man:

Excellent.

Interviewer:

But we are no closer to the rule!! [laughter] I want you to get to the rule.

Couple 2:

How about 1, 7, 13

Interviewer:

Follows the rule

Couple 2:

What? 11, 12, 13

Interviewer:

Follows the rule

Couple 2 - woman:

How does this make sense? I don’t know how to do this.

Couple 2 – man:

10, 9, 8

Interviewer:

Does not follow the rule>

Couple 2:

10, 9, 8 does not.

Couple 2:

Oh, so is it all in ascending order?

Interviewer:

Booyah! Up top [interviewer and couple high-five]

Couple 2:

Okay

Interviewer:

Booyah! Up top [interviewer and couple high-five]

Interviewer:

Yes! First ones to get it. You guys nailed it, that’s the rule. That’s the rule! Numbers in increasing order.

Couple 1:

Ohhhhh

Interviewer:

Numbers in ascending order

Couple 4:

[An older man in bright blue wind jacket, grey hair and sunglasses with an older woman with auburn hair, grey wind jacket and a green scarf.]

Oh, so much easier than we thought.

Interviewer:

1, 2, 3, 4, 5, 6, 10, 15, 25. Doesn’t matter. Any numbers in ascending order.

I was inspired to make this video by the book ‘The black swan’, by Nassim Taleb. Now the black swan is a metaphor for the unknown and the unexpected. I mean, In the old world the theory was that all swans were white. So each instance of a white swan would make you think, yeah, that theory is pretty good. But the point is you can never prove a theory true and in fact when people found Australia they realised that there were black swans. What was interesting for me was that everyone I spoke to came up with a rule very early on and then only proposed numbers that fit with that rule they were thinking.

Interviewer:

I was looking for you guys to propose a set of numbers that didn’t follow your rule and didn’t follow your rule.

Couple 4:

Oh right

Interviewer:

I was looking for you guys not to try to confirm what you believe.

You are always asking something where you expect the answer to be yes, right?

Couple 2:

Yeah

Interviewer:

Like you’re trying to get at it

Couple 2:

But instead you want to get the ‘no’.

Interviewer:

You want to get the ‘no’ because that’s much more informational for you than the ‘yes’. Like if everything is given a yes …

Couple 2:

No, that is true, that is really true once you say that.

Interviewer:

That is so important about the scientific method. We set out to disprove our theories. And it’s when we can’t disprove them that we say, ‘this must be getting at something really true about our reality’. So I think we should do that in all aspects of our lives. If you think that something is true you should try as hard as you can to disprove it. Only then can you really get at the truth and not fool yourself.

[End of transcript]

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