Answer:
a) false
b) true
c) true
d) true
e) false
Step-by-step explanation:
In a statement of the type:
p ∧ q
where ∧ means "and"
The statement is true only if both p and q are true
the statement is false if p, q, or both, are false.
and in the case of:
p ∨ q
where ∨ means "or"
The statement is true if at least one of p or q (or both) are true.
The statement is false if both are false.
Now that we know that, let's solve the problem:
a) "5 is an odd number and 3 is a negative number."
Here we have:
p = 5 is an odd number
We know that this is true
q = 3 is a negative number
This is false.
then the complete statement is false.
b) "5 is an odd number or 3 is a negative number."
here we have:
p = 5 is an odd number.
this is true
q = 3 is a negative number
because in this case we have an "or", with only p being true, the whole statement is true.
c) "8 is an odd number or 4 is not an odd number."
p = 8 is an odd number (this is false)
q = 4 is not an odd number (this is true, 4 is a even number)
Again, we have an "or", so we need only one true proposition, then the statement is true.
d) "6 is an even number and 7 is odd or negative."
p = 6 is an even number (true)
q = 7 is odd or negative (notice that we have an or, and 7 is odd is true, so this proposition is true)
Then both propositions are true, then the statement is true.
e) "It is not true that either 7 is an odd number or 8 is an even number (or both)."
This is most complex, this will be true if at least one of the propositions is false.
but:
7 is an odd number is true
8 is an even number is true.
Then both statements are true, which means that the statement is false.
