4. Lee will do well if and only if she studies. She will study only if logic is interesting. Logic is interesting only if it is easy, which it is not. Therefore, Lee will not do well.

QPB, PRC, RSC, SN |- QN

1. QPB
2. PRC
3. RSC
4. SN \show QN
5. SNRNC....4 C subs
6. RN.......4,5 C elim
7. RNPNC....2 C elim
8. PN.......6,7 C elim
9. QNPOPNQOA...1 AB subs
10. QNPO..... 9 A elim
11. QN....... 8,10 O elim