What is the Answer to 1/3(10) using Logic?

[adjacent]

Homework Statement

$\frac{1}{2}(5)=3$ , based on this logic, what is $\frac{1}{3}(10)$?

The Attempt at a Solution

In real life, $\frac{1}{2}(5)=2.5$ so
2.5 --> 3
Just like that, $\frac{1}{3}(10)=\frac{10}{3}$
so
2.5 --> 3
10/3 -->x

Cross multiply---
x=4
I am not very sure whether this is correct or not. I don't know what logic this question assumes. Proportion or addition?

 

[micromass]

You haven't described a logic yet. You have to state all the rules you are using. Just by stating that $5/2=3$ doesn't get you anywhere, because the only thing it implies is that $5/2=3$, nothing else.

 

[adjacent]

You haven't described a logic yet. You have to state all the rules you are using. Just by stating that $5/2=3$ doesn't get you anywhere, because the only thing it implies is that $5/2=3$, nothing else.

I don't understand

 

[micromass]

I don't understand

Can you list all the rules (axioms) of your system?

 

[adjacent]

Can you list all the rules (axioms) of your system?

Are you asking what I assumed?
We know that(From the question) $\frac{5}{2}=3=2.5$ So what I assumed is
$3=k2.5$ | $k=1.2$
Let $i$ be the false(Logic of the question) value and $r$ be the true value
Then $i=1.2r$
So $x=1.2 \times \frac{10}{3}$
$x=4$

 

[CAF123]

I don't understand

5/2 = 3 is simply a statement - there is nothing you can extrapolate from this to answer your question. The real number system obeys a set of axioms, so similarly there must exist a set of axioms that your system has to adhere to. Was there more given in the question or in an earlier exercise perhaps?

 

[adjacent]

Was there more given in the question or in an earlier exercise perhaps?

That is the problem. I wrote exactly as the question was written. This is not an exercise, I saw this from the internet.

So the question cannot be answered without knowing what rules it obeys();?

 

[micromass]

That is the problem. I wrote exactly as the question was written. This is not an exercise, I saw this from the internet.

So the question cannot be answered without knowing what rules it obeys();?

The question as you asked in your OP cannot be answered. You need more information (such as other rules that the system obeys).

 

[adjacent]

Oh, I get it now. I see questions like these all over the internet. They normally use proportion.
Anyway,thanks