# Math Help - validity

1. ## validity

determine the validity of the following argument
S1:Babies are illogocal
S2:Nobody is despised who can manage a crocodile
S3:Illogical people are despised

S:Babies cannot manage crocodiles
s1,s2,s3 are the premises and S is the conclusion

2. Originally Posted by Rose Wanjohi
determine the validity of the following argument
S1:Babies are illogocal
S2:Nobody is despised who can manage a crocodile
S3:Illogical people are despised

S:Babies cannot manage crocodiles
s1,s2,s3 are the premises and S is the conclusion
Rose Wanjohi
Why do you simply post a series of question with no attemp at a solution?
Do you expect an answer freely given to each?

3. i just ask them for more practise and to challenge my fellow members anyway i get what you mean i will do exactly that at first i wasn't sure anything i wrote would be considered but am cool now thnx

4. I always find it easier to replace these statements with just variables
1) $a\Rightarrow b$ baby implies illogical
3) $b\Rightarrow c$ illogical implies despised.
2) $d \Rightarrow \sim c$ can manage a croc implies not despised

For 2 I find it easier to work with the contrapositive,
which would be $c \Rightarrow \sim d$ despised implies cannot handle a croc.

now I think you can string these together to reach a conclusion that the statement cannot be true.

5. Originally Posted by Rose Wanjohi
determine the validity of the following argument
S1:Babies are illogocal
S2:Nobody is despised who can manage a crocodile
S3:Illogical people are despised
S:Babies cannot manage crocodiles
Here is another way of thinking about it.
The set of babies is a subset of the illogical.
The set of illogicals is a subset of the set of despised.
The set of despised is disjoint from the set of crocodile mangers.

Do you conclusion follow?

6. Originally Posted by Plato
Here is another way of thinking about it.
The set of babies is a subset of the illogical.
The set of illogicals is a subset of the set of despised.
The set of illogicals is disjoint from the set of crocodile mangers.

Do you conclusion follow?
Think you mean despised, but yeah since illogicals is a subset of this, this is also true. That is a nice way of thinking about it too.

7. Originally Posted by Gamma
Think you mean despised, but yeah since illogicals is a subset of this, this is also true. That is a nice way of thinking about it too.
Yes of course. Thank you for the correction.

BTW. That idea is probably the way the 19th century English mathematician/logician Venn used his now famous Venn Diagrams