2. Lee will study if logic is interesting. Unless she studies she will not do well. Logic is interesting. Therefore, Lee will do well.
RPC, PQNO, R |- Q
On the symbolization it is important to remember that the first sentence expresses the idea that logic being interesting is a sufficient condition and so must be symbolized to the left in the string. In the resulting pattern we can see that we are not negating one of the two disjuncts in the second string (required to use O elim), and the resulting pattern is not valid.
PQR || RPC | PQNO | R | Q
.101......111......1011....1....0