Little do they know that a third party—Sausage Saloon—has sent you to take advantage of the situation.

意粉宮一個名廚

As their top spy, your skills range from infiltration and subterfuge, to safe cracking and reading faces for signs of deception.

被漢堡殿的特工擄走了

You've tracked the captors to where they're holding the chef prisoner.

想套出秘醬配方收藏的地點

From your hiding spot, you can see him on the other side of the glass, while in front of you an interrogator wearing headphones speaks into a microphone.

殊不知黃雀在後

"We already know the recipe is on the 13th floor of the bank vault, in a safe deposit box numbered between 13 and 1300.”

三分鼎足的熱狗城

"Now tell us, is the number less than 500?”

特派你潛入，希望漁人得利

You can't hear the chef's answer, but you can see that he's lying.

臥底佯裝、詭計多端、智破保險庫

The interrogator, however, falls for it.

眉目悉謊言就是你這大密探的武器

He follows up by asking, "Is it a perfect square?”

你追蹤綁匪，找到名廚俘虜的位置

Again, you can't hear the answer but can tell the chef is lying, while the interrogator takes him at his word.

暗中視察，看到囚在玻璃後的名廚

He then asks, "is it a perfect cube?”

眼前則有審問者，頭戴耳機

This time the chef answers truthfully.

對著麥克風說話

The interrogator thinks for a minute and says, "Good. now if you just tell me whether or not the number's second digit is a one, we'll be done here.”

「我們查出秘方藏在保險庫 13 樓

But as the chef starts to answer, the interrogator stands up, blocking your view.

編號 13 至 1300 其中一個保險箱

Within moments, he rushes out of the room, announcing that he's got the answer, and is sending agents to retrieve the recipe.

請回答：編號是否小於 500？」

You know that the Burger Bazaar people have the wrong box number, but can you figure out the right one and retrieve the recipe yourself?

聽不到名廚答話但看得出他在撒謊

Pause the video to figure it out for yourself.

審問者卻不虞有詐

Answer in 3

續問：「編號是否完全平方數？」

Answer in 2

你同樣聽不到答案但看出他在撒謊

Answer in 1

但審問者深信不疑

The key here is to work backwards.

再問：「編號是否完全立方數？」

We don't know what the chef answers to the final question or whether he answers truthfully.

今次名廚如實作答

But we do know that by the time the interrogator asks it, he's narrowed the options down to two numbers - one where the second digit is 1, and one where it isn't.

審問者想了一想，然後說

Our goal, then, is to find answers to the previous questions that lead to just two possibilities.

「最後一條：編號第二位數是否 1

Of the three constraints offered, the one that narrows our options the most is if the number is a perfect cube.

答完這條就好了」

That leaves us with only eight answers between 13 and 1300.

就在名廚正要作答時

So let's assume the answer to the third question was a truthful yes.

審問者站了起來，遮擋了你的視線

Now, let's look at the second question.

一瞬間他就衝出了房間

If the chef answered yes to the number being a perfect square, it would narrow the interrogator's options to just 64 and 729 - the only numbers in our range that are both a square and a cube.

說他找到答案了，正派人取秘方

But neither of these has a 1 as the second digit.

你知道漢堡殿找錯了編號

So the given answer to the second question must've been no.

但你能否得出正確編號找到秘方？

And that also means we can eliminate these two squares from the interrogator's list, leaving only six numbers.

要嘗試解謎，請按一下「暫停」

Now for the first question, which allows us to divide this list.

揭曉倒數：3

If the chef answered yes to the number being less than 500, we'd have four options, which is too many.

揭曉倒數：2

But a no leaves us with two numbers greater than 500, one of which does have a 1 as its second digit.

揭曉倒數：1

We don't know which of these numbers the interrogator thinks is correct, but that doesn't matter - remember, his conclusion was based on lies.

解題關鍵是用倒推法

You, on the other hand, are now in a position to reconstruct the truth.

最後一條的答案，我們不知道

First, the chef said the number was greater than 500, but lied, meaning it's actually less than 500.

亦不知道那一題名廚是否說實話

Second, the chef said it wasn't a perfect square, but lied again, meaning the number is indeed a square.

但我們知道，審問者問那一題時

And finally, he truthfully confirmed that it was also a cube.

心中把數字收窄到兩個數字

And as we've already seen, the only number under 500 that's both a square and a cube is 64.

一個第二位數是 1，另一個不是 1

You find the secret recipe and are gone before anyone's the wiser.

我們的目標就是找出之前的問題

Corporate espionage is not an easy game - but sometimes, that's just how the sausage is made.

甚麼答案只得出兩個可能數

Don't take a break just yet - the world needs you.

三項制限中

An evil syndicate is primed to use its powerful death ray.

最能收窄範圍的是完全立方數這條

Use your espionage skills to infiltrate their secret lair and save us all.

從 13 到 1300 可篩出僅 18 個數字