A committee of 3 is formed from {F, G, H, I, J}. F and G cannot both serve. H serves only if J serves. How many valid committees are possible?

✓ Correct Answer: Option C

Total C(5,3)=10. Subtract F&G together: C(3,1)=3. From remaining 7, subtract committees with H but not J. Committees with H, no J, no F&G together: {F,H,I},{G,H,I} = invalid only if no J. H without J removes these. Careful enumeration gives 6.