As a homework I got the following question.
Say whether or not the following argument is a valid argument. Explain your answer.
(a) Successful candidates for this job must have either a Bachelor's degree or five years of work experience
(b) Alvin has a Master’s degree
(c)Alvin got the job
(d) ∴ Johnny does not have five years of work experience
The way I tried to approach this was using the inference logic rules, I translated the previous statement as follows:
$p \implies (q \lor r)$
$q$
$p$
And combined the first and third line Using the Modus Ponens rule to reduce it as follows
$(q \lor r) \land q $ or in the notation I used earlier
$(q \lor r)$
$q$
I'm now asking myself if this is a valid thing to do?