Answer
Use Modus Ponens twice.
Work Step by Step
Let us assume
p=“Randy works hard”
q="Randy is a full boy"
r="Randy will get the job"
We can write the given statements as:
1) “Randy works hard” $\equiv p$
2) “If Randy works hard, then he is a dull boy,” $\equiv p \to q$
3) “If Randy is a dull boy, then he will not get the job” $\equiv q \to \neg r$
So we have
1) $ p$
2) $p \to q$
3) $q \to \neg r$
4) Using Modus ponens to 1) and 3) , we get
$ q$
5) Using Modus ponens to 3) and 4) , we get
$\neg r$
$\neg r$ means that Randy will not get the job which is the given conclusion.
