Proof from Axioms

Question

Given the axioms

Henry owns a bike
Every bike owner loves racing
No one who loves racing buys a scooter.
Either Henry or Bob bought a scooter, which is named Bill

Did Bob buy the scooter?

This is a homework question; it seems almost too easy, so I just want to check to make sure my logic is correct.

Since either Henry or Bob bought a scooter, and since Henry owns a bike and therefore loves racing and therefore cannot buy a scooter, then Bob must have been the one to buy the scooter.

Am I correct in my logic and my answer?

I'm voting to close this question as off-topic because it is about logic instead of directly about programming or software development. — Pang, Dec 12 '15 at 04:24

score 0 · Accepted Answer · answered Dec 08 '15 at 09:06

0

Legend:

Owns a bike === A
Loves racing === B
Buys a skooter === C

Rephrase the logic conditions:

Henry is A
A => B
B => Not(C)
Henry or Bob is C

Calculations:

Henry is A => Henry is B => Henry is Not(C) => Bob is C
Meaning: Bob bought a skooter

So yes - you are correct. If it seems easy, it may be just to understand the tools you should use, to get you ready for more complex problems.

answered Dec 08 '15 at 09:06

Lavi Avigdor

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Sorry, the contrast on my screen didn't let me see the check mark, so I tried to upvote, but I don't have enough reputation yet. :) – Arty Dec 08 '15 at 12:07

Proof from Axioms

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