The word is "prove", not "solve" 1. (F v G) > (H & I) 2. I > K 3. ~K. : ~F 4. ~I 2,3, Modus tollens 5. ~I v ~H 4, Addition 6. ~H v ~I 5, Commutation 7. ~(H & I) 6, DeMorgan 8. ~(F v G) 1,7, Modus tollens 9. ~F & ~G 8, DeMorgan 10. ~F 9, Simplification Edwin