Question

If p -> q, then ~ q -> ~ P is true.

Answer 1

T/F?

Answer 2

look up 'contrapositive'

Answer 3

I know what a contrapositive is.

Answer 4

Construct a truth table, where the conditional \[P\rightarrow Q\] evaluates to ~\[PorQ\]

Answer 5

I don't understand...

Answer 6

do you know how to make a truth table?

Answer 7

Basically a contrapositive is another way of expressing a conditional statement in a negative form, if you actually knew what it meant you'd already have an answer!

Answer 8

if you know what the contrapositive is then you should know the answer

Answer 9

I am very familiar with what a contrapositive is; I do not understand the context of the question.

Answer 10

Thank you for the fantastic help. It is quite ridiculous you can't get decent help on website meant for helping people. I am not asking for you to give me an answer, but to explain how to get it. I also do not appreciate being told that if I "ACTUALLY" knew what it meant, that I would know the answer, implying I am lying and do not know that a contrapositive is taking a given conditional statement and negating it as well as interchanging each part of the sentence. I clearly knew that, yet still was/am unsure what the question is asking. I guess I will just go with my gut and say true, but the responses, ASSUMPTIONS about what I know, and quite frankly the attitude implied is awful.

Answer 11

Sorry you feel that way.

A quick Google search on the contrapositive would lead you to the answer.

what you have typed above is almost the contapositive ( it is one of the implication and is therefore true)

I reiterate what I stated above. If you understood exactly what the contapositive was saying then you would know the answer. if you have to 'go with your gut' then you really don't know it.

Answer 12

Believe me, I did much more than a quick google search and failed to find anything near an answer. No matter how you cut it, I don't understand the connection between this and contrapositives, unfortunately, and have done numerous assignments regarding them. If you insist that I do not understand a contrapositive, than so be it; maybe my lesson did not cover this subject well enough, as I did not see anything similar to this question throughout the whole lesson. I am sure you are right in saying that someone should understand the above question if they know what a contrapositive is. That does not mean I do not deserve an explanation that guides me towards the answer, rather than redirecting me to google...thanks for your opinion though.

Answer 13

Basically a conditional statement and its conrapositive are equivalent, they have the same meaning but are expressed differently. e.g
Conditional: If john works hard, then he'll pass the exams
Contrapositive: If john didn't pass the exams, then he didn't work hard

Answer 14

Thank you, but I did know that already. All I don't know is what p, q and ~ means...

Answer 15

p and q are statements, in my example p is john works hard and q is john will pass the exams, ~ is just negation like, ~p means john doesn't work hard.

Answer 16

Thank you very much. That is exactly what I needed help with! I had no clue the meant negation. It makes much sense now.