Tell whether each proposition is true, is false, or has unknown status at this time.

p is true

q is false

r's status is unknown at this time

Tell whether each proposition is true, is false, or has unknown status at this time.

q --> r (I know this would be true because if the hypothesis is false, the truth value is always true)

(p^r) <--> r (The textbook says the answer is true but how would I know this? All I know is that p is true, so if I don't know r it can be either true or false)

(q or r) <--> r (The textbook says this is true but I don't get how. All I know is q is false)

Please help :(

Re: Tell whether each proposition is true, is false, or has unknown status at this ti

Quote:

Originally Posted by

**kmjt** p is true

q is false

r's status is unknown at this time

Tell whether each proposition is true, is false, or has unknown status at this time.

q --> r (I know this would be true because if the hypothesis is false, the truth value is always true)

(p^r) <--> r (The textbook says the answer is true but how would I know this? All I know is that p is true, so if I don't know r it can be either true or false)

(q or r) <--> r (The textbook says this is true but I don't get how. All I know is q is false)

ia always true because if both sides are true and if both sides are false.

Re: Tell whether each proposition is true, is false, or has unknown status at this ti

Quote:

Originally Posted by

**Plato** ia always true because if

both sides are true and if

both sides are false.

I do not quite understand :(

Re: Tell whether each proposition is true, is false, or has unknown status at this ti