logic problem

[solemn sail]

There are 5 lockers placed next to each other on a wall, in the order: A, B, C, D, E- We know that the key to A also opens E, the key to C also opens B and each key opens at least one of the adjacent lockers. How many keys do we need, at a minimum, to open all the lockers

the book says the answer is 1

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[magic elm]

So weirdly written

"each key opens at least one of the adjacent lockers" you don't know which one?

[solemn sail]

no

you don’t

[magic elm]

Or you have to open D or the book is wrong

[solemn sail]

idk i don’t think it’s wrong

like i think

if we have the key to c

it also openes b

the only adjacent of A is b

so b’s key openes A too

and if B’s key openes A

it says the key that openes A also openes E

so we can unlock E

@magic elm

do you think this is correct

[magic elm]

Yup that's right

[tropic token]

I think perhaps you didn't state it exactly correctly, which matters a lot.

[solemn sail]

it’s like this

[tropic token]

Because you understand that there's a distinction between the key to a locker and a key that opens a locker, right?

[solemn sail]

no

💀

[tropic token]

The key to A is the one and only key that is designed to open A. It may also open B, but it's not the key to B, that would be a different key.

Think about the distinction in a hotel between the key to room 402 and the master key.

[solemn sail]

oh yes

bro

can you tell me

how to solve that problem

[tropic token]

Can you give us a screenshot of the problem as originally worded?

[solemn sail]

ok

number 92

(it’s italian)

you can translate it

[solemn sail]

92. There are 5 lockers placed next to each other on a wall, in the order:
    A, B, C, D, E. We know that the key of A also opens E, the key of C also opens B, and each key opens at least one of the adjacent lockers. How many keys do we need, at a minimum, to open all the lockers?

this is the translation

[tropic token]

Yeah, the problem is poorly stated. The key to A also opens E is different from saying every key that opens A also opens E, and "each key opens at least one of the adjacent lockers" is ambiguous, because does it only open one of the lockers adjacent to the locker it belongs to, or adjacent to every other locker it opens?

[solemn sail]

idk

i think it openes the one u wnat

want

[tropic token]

...I know you don't know. You don't know because the problem doesn't tell you. That's what makes the problem poorly written.

[solemn sail]

it says the answer is 1

how can we get to 1

[solemn sail]

wait

it says it openes atleast 1 of the adjacent lockers

it can mean it openes both

[tropic token]

...not remotely the problem.

[solemn sail]

i’m gonna shower hope you can solve it or i will have to skip the problem

[tropic token]

The problem as stated DOES NOT HAVE an answer. There is not enough information.

That's what I mean when I say the problem is poorly stated.

I think the answer is actually 3. Take the key to A, which also opens E and B, and then you need the keys to C and D.

[tropic token]

But it's important to note that the question is poorly stated and not specific enough. We had to make assumptions about what it was saying to reach that result, and the reason we got a different answer is presumably because my assumptions were more conservative than the gap between what the question says and what the question meant.