# A logical question

1. Aug 14, 2008

### some_one

martha wants to buy a fast and a chip car which answers to this term:
the car should be painted in silver or a convertible ,but not both.

which one of the following arguments will lead us to the conclusion
that martha will not find a car which fits by her demands?
1.a fast car which is not chip,unless its painted in silver and it a convertible
2.a fast car painted in silver,but its not a convertible
3.a chip car will never be painted in silver
4.a convertible car are not fast and they are not painted in silver

2. Aug 15, 2008

### CompuChip

So let's define some properties:
F: the car is fast
Ch: the car is cheap
S: the car is painted silver
Co: the car is convertible

Now can you make a logical expression which is true when she does buy the car? So I'm looking for something of the form: (F or Ch) and (F and ((not Co) or S).
Also try to express the answer possibilities this way (as an example, number 1 would become: $(F \wedge \neg Ch) \vee (S \wedge Co)$).

Once you have that, I will of course ask you if you can negate that expression.

3. Aug 15, 2008

### Werg22

I doubt the OP has experience with formal logic, let alone symbolic logic, CompuChip.

4. Aug 15, 2008

### CompuChip

Is there an easier way to solve it, then?

By the way I just noticed this is posted in "general discussion > brain teasers" so maybe the question is for us to find the answer and the OP already has it.

5. Aug 15, 2008

### some_one

i am having the final answer
bur i dont have the way its being solved

6. Aug 15, 2008

### some_one

i think i got the way they solved it
its 1
because in that way the car will be silver and convertible
which is not possible