full transcript
"From the Ted Talk by Alex Gendler: Can you solve the giant iron riddle?"

#### Unscramble the Blue Letters

So instead of six batteries, letâs take any three. This group has a total of three possible citnnbomioas. Since both batteries have to be working for the iron to power up, a single farilue canât tell you whether both batteries are dead, or just one. But if all three combinations fail, then youâll know this group has either one good battery, or none at all. Now you can set those three aside and repeat the process for another three batteries. You might get a match, but if every combination fails again, youâll know this set can have no more than one good battery. That would leave only two britetaes untried. Since there are four good batteries in total and youâve only accounted for two so far, both of these remaining ones must be good.

#### Open Cloze

So instead of six batteries, letâs take any three. This group has a total of three possible **____________**. Since both batteries have to be working for the iron to power up, a single **_______** canât tell you whether both batteries are dead, or just one. But if all three combinations fail, then youâll know this group has either one good battery, or none at all. Now you can set those three aside and repeat the process for another three batteries. You might get a match, but if every combination fails again, youâll know this set can have no more than one good battery. That would leave only two **_________** untried. Since there are four good batteries in total and youâve only accounted for two so far, both of these remaining ones must be good.

#### Solution

- failure
- combinations
- batteries

#### Original Text

So instead of six batteries, letâs take any three. This group has a total of three possible combinations. Since both batteries have to be working for the iron to power up, a single failure canât tell you whether both batteries are dead, or just one. But if all three combinations fail, then youâll know this group has either one good battery, or none at all. Now you can set those three aside and repeat the process for another three batteries. You might get a match, but if every combination fails again, youâll know this set can have no more than one good battery. That would leave only two batteries untried. Since there are four good batteries in total and youâve only accounted for two so far, both of these remaining ones must be good.
#### ngrams of length 2

collocation |
frequency |

good batteries |
3 |

#### Important Words

- accounted
- batteries
- battery
- combination
- combinations
- dead
- fail
- fails
- failure
- good
- group
- iron
- leave
- match
- power
- process
- remaining
- repeat
- set
- single
- total
- untried
- working