full transcript
#### From the Ted Talk by Ganesh Pai: Can you solve the passcode riddle?

## Unscramble the Blue Letters

In this dystopian world, your resistance group is humanity's last hope. Unfortunately, you've all been creuptad by the tnniycraal rulers and bghurot to the ancient colosseum for their deadly entertainment. Before you're thrown into the dungeon, you see many nmbureed hallways lnadeig outside. But each exit is blocked by an electric barrier with a combination keypad. You learn that one of you will be allowed to try to escape by passing a challenge while everyone else will be fed to the mutant salamanders the next morning. With her peerfct logical reasoning, Zara is the obvious chioce. You hand her a concealed audio transmitter so that the rest of you can listen along. As Zara is led away, you hear her footsteps echo through one of the hallways, then stop. A voice announces that she must enter a code consisting of three psoivite whole numbers in ascending order, so the second number is gtreaer than or equal to the first, and the third is greater than or equal to the second. She may ask for up to three clues, but if she makes a wrong guess, or says anything else, she'll be thrown back into the dungeon. For the first clue, the voice says the product of the three numbers is 36. When Zara asks for the second clue, it tells her the sum of the numbers is the same as the number of the hallway she etenred. There's a long snliece. You're sure Zara rebmremes the hallway number, but there's no way for you to know it, and she can't say it outloud. If Zara could enter the pdosacse at this point, she would, but instead, she asks for the third clue, and the vcoie announces that the largest number appears only once in the combination. Moments later, the buzz of the eictelrc biearrr stops for a few seconds, and you realize that Zara has escaped. Unfortunately, her transmitter is no logenr in range, so that's all the information you get. Can you find the solution? Pause on the next screen to work out the soouiltn. 3 2 1 You're worried about the fact that you don't know Zara's hallway number, but you dedice to satrt from the bniningeg anyways. From the first clue, you work out all of the eight possible combinations that come out to a product of 36. One of these must be right, but which one? Now comes the hard part. Even though you don't know which number you're looking for, you decide to work out the sum of each combination's three numbers. That's when it hits you. All but two of the sums are unique, and if the hllaawy number had matched any of these, Zara would have known the cecrrot combination right then and there without asking for the third clue. Since she did ask for the clue, the hallway number must have matched the only sum that appears more than once in the list: thirteen. But which of the two combinations that add up to thirteen is correct: 1,6,6, or 2,2,9? That's where the third clue comes in. Since it tlles us that the largest number must be uiuqne, 2,2,9 must be the code. When night falls, you and the others escape through hallway thirteen and rejoin Zara outside. You've freed yourselves through math and loigc. Now it's time to free the rest of the world.
## Open Cloze

In this dystopian world, your resistance group is humanity's last hope. Unfortunately, you've all been **________** by the **__________** rulers and **_______** to the ancient colosseum for their deadly entertainment. Before you're thrown into the dungeon, you see many **________** hallways **_______** outside. But each exit is blocked by an electric barrier with a combination keypad. You learn that one of you will be allowed to try to escape by passing a challenge while everyone else will be fed to the mutant salamanders the next morning. With her **_______** logical reasoning, Zara is the obvious **______**. You hand her a concealed audio transmitter so that the rest of you can listen along. As Zara is led away, you hear her footsteps echo through one of the hallways, then stop. A voice announces that she must enter a code consisting of three **________** whole numbers in ascending order, so the second number is **_______** than or equal to the first, and the third is greater than or equal to the second. She may ask for up to three clues, but if she makes a wrong guess, or says anything else, she'll be thrown back into the dungeon. For the first clue, the voice says the product of the three numbers is 36. When Zara asks for the second clue, it tells her the sum of the numbers is the same as the number of the hallway she **_______**. There's a long **_______**. You're sure Zara **_________** the hallway number, but there's no way for you to know it, and she can't say it outloud. If Zara could enter the **________** at this point, she would, but instead, she asks for the third clue, and the **_____** announces that the largest number appears only once in the combination. Moments later, the buzz of the **________** **_______** stops for a few seconds, and you realize that Zara has escaped. Unfortunately, her transmitter is no **______** in range, so that's all the information you get. Can you find the solution? Pause on the next screen to work out the **________**. 3 2 1 You're worried about the fact that you don't know Zara's hallway number, but you **______** to **_____** from the **_________** anyways. From the first clue, you work out all of the eight possible combinations that come out to a product of 36. One of these must be right, but which one? Now comes the hard part. Even though you don't know which number you're looking for, you decide to work out the sum of each combination's three numbers. That's when it hits you. All but two of the sums are unique, and if the **_______** number had matched any of these, Zara would have known the **_______** combination right then and there without asking for the third clue. Since she did ask for the clue, the hallway number must have matched the only sum that appears more than once in the list: thirteen. But which of the two combinations that add up to thirteen is correct: 1,6,6, or 2,2,9? That's where the third clue comes in. Since it **_____** us that the largest number must be **______**, 2,2,9 must be the code. When night falls, you and the others escape through hallway thirteen and rejoin Zara outside. You've freed yourselves through math and **_____**. Now it's time to free the rest of the world.
## Solution

- perfect
- electric
- numbered
- tells
- silence
- voice
- positive
- unique
- remembers
- logic
- entered
- brought
- decide
- hallway
- passcode
- choice
- solution
- longer
- greater
- beginning
- start
- captured
- tyrannical
- leading
- barrier
- correct

## Original Text

In this dystopian world, your resistance group is humanity's last hope. Unfortunately, you've all been captured by the tyrannical rulers and brought to the ancient colosseum for their deadly entertainment. Before you're thrown into the dungeon, you see many numbered hallways leading outside. But each exit is blocked by an electric barrier with a combination keypad. You learn that one of you will be allowed to try to escape by passing a challenge while everyone else will be fed to the mutant salamanders the next morning. With her perfect logical reasoning, Zara is the obvious choice. You hand her a concealed audio transmitter so that the rest of you can listen along. As Zara is led away, you hear her footsteps echo through one of the hallways, then stop. A voice announces that she must enter a code consisting of three positive whole numbers in ascending order, so the second number is greater than or equal to the first, and the third is greater than or equal to the second. She may ask for up to three clues, but if she makes a wrong guess, or says anything else, she'll be thrown back into the dungeon. For the first clue, the voice says the product of the three numbers is 36. When Zara asks for the second clue, it tells her the sum of the numbers is the same as the number of the hallway she entered. There's a long silence. You're sure Zara remembers the hallway number, but there's no way for you to know it, and she can't say it outloud. If Zara could enter the passcode at this point, she would, but instead, she asks for the third clue, and the voice announces that the largest number appears only once in the combination. Moments later, the buzz of the electric barrier stops for a few seconds, and you realize that Zara has escaped. Unfortunately, her transmitter is no longer in range, so that's all the information you get. Can you find the solution? Pause on the next screen to work out the solution. 3 2 1 You're worried about the fact that you don't know Zara's hallway number, but you decide to start from the beginning anyways. From the first clue, you work out all of the eight possible combinations that come out to a product of 36. One of these must be right, but which one? Now comes the hard part. Even though you don't know which number you're looking for, you decide to work out the sum of each combination's three numbers. That's when it hits you. All but two of the sums are unique, and if the hallway number had matched any of these, Zara would have known the correct combination right then and there without asking for the third clue. Since she did ask for the clue, the hallway number must have matched the only sum that appears more than once in the list: thirteen. But which of the two combinations that add up to thirteen is correct: 1,6,6, or 2,2,9? That's where the third clue comes in. Since it tells us that the largest number must be unique, 2,2,9 must be the code. When night falls, you and the others escape through hallway thirteen and rejoin Zara outside. You've freed yourselves through math and logic. Now it's time to free the rest of the world.
## Frequently Occurring Word Combinations

### ngrams of length 2

collocation |
frequency |

electric barrier |
2 |

voice announces |
2 |

largest number |
2 |

hallway number |
2 |

## Important Words

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