Determine the validity of the argument. I have this question and was hoping I could get some help on it:
p∧q∧r → s
u →s
p∧u∧~r
∴q
I have found:
p is true
u is true
~r is true 
r is false.
But I am unsure what to do to find the validity of the statement. 
My thinking is that premise 1 is (~p ∨ ~q ∨ ~r) ∨ s where S is true but I get stuck here. 
Hopefully this made sense and thank you for your assistance!

No, $q$ does not follow. You can try it with $q$ both ways and see.
As you said, the third premise means $p$ is True, $u$ is True, and $r$ is False. Then the second premise means $s$ is True.
If $q$ is True, the first premise says $T \wedge T \wedge F \to T$, which is fine.
If $q$ is False, the first premise says $T \wedge F \wedge F \to T$, which is fine.
So we can conclude nothing about $q$.
