1. All corporations that overcharge their customers are unethical businesses.

Some unethical businesses are investor-owned utilities.

Therefore, some investor-owned utilities are corporations that overcharge their customers.

2. No fossil fuels are renewable forms of energy.

Some combustible gases are fossil fuels.

Therefore, some combustible gases are not renewable forms of energy.

3. No individuals truly concerned with the plight of suffering humanity are people motivated primarily by self-interest.

All television evangelists are people motivated primarily by self-interest.

Therefore, some television evangelists are not individuals truly concerned with the plight of suffering humanity.

4. All high-fat diets are diets high in cholesterol.

Some diets high in cholesterol are not healthy food programs.

Therefore, some healthy food programs are not high-fat diets.

5. No engineering majors are candidates for nightly hookups.

No candidates for nightly hookups are deeply emotional individuals.

Therefore, no deeply emotional individuals are engineering majors.

Use Venn diagrams to determine whether the following standard-form categorical syllogisms are valid from the Boolean standpoint, valid from the Aristotelian standpoint, or invalid. Then, identify the mood and figure, and cross-check your answers with the tables of valid syllogisms found in Section 5.1.