Use conversion, obversion, and contraposition to determine whether the following arguments are valid or invalid. For those that are invalid, name the fallacy committed.

★1. All commodity traders are gamblers who risk sudden disaster.

Therefore, all gamblers who risk sudden disaster are commodity traders.

2. No child abusers are people who belong in day-care centers.

Therefore, all child abusers are people who do not belong in day-care centers.

3. Some states having limited powers are not slave states.

Therefore, some free states are not states having unlimited powers.

★4. Some insane people are illogical people.

Therefore, some logical people are sane people.

5. Some organ transplants are not sensible operations.

Therefore, some organ transplants are senseless operations.

6. No individuals who laugh all the time are people with a true sense of humor.

Therefore, no people with a true sense of humor are individuals who laugh all the time.

★7. All periods when interest rates are high are times when businesses tend not to expand.

Therefore, all times when businesses tend to expand are periods when interest rates are low.

8. Some swimsuits are not garments intended for the water.

Therefore, some garments intended for the water are not swimsuits.

9. No promises made under duress are enforceable contracts.

Therefore, no unenforceable contracts are promises made in the absence of duress.

★10. All ladies of the night are individuals with low self-esteem.
Therefore, no ladies of the night are individuals with high self-esteem.
11. Some graffiti writers are artists relieving pent-up frustrations.
Therefore, some artists relieving pent-up frustrations are graffiti writers.
12. Some peaceful revolutions are episodes that erupt in violence.
Therefore, some episodes that do not erupt in violence are non-peaceful revolutions.
★13. Some insurance companies are not humanitarian organizations.
Therefore, some humanitarian organizations are not insurance companies.
14. Some fossil fuels are unrenewable energy sources.
Therefore, some fossil fuels are not renewable energy sources.
15. All hired killers are criminals who deserve the death penalty.
Therefore, all criminals who deserve the death penalty are hired killers.
★16. No nonprescription drugs are medicines without adverse effects.
Therefore, no medicines with adverse effects are prescription drugs.
17. All fire-breathing dragons are lizards that languish in soggy climates.
Therefore, no fire-breathing dragons are lizards that flourish in soggy climates.
18. Some distant galaxies are not structures visible to the naked eye.
Therefore, some structures visible to the naked eye are not distant galaxies.
★19. All unpleasant experiences are things we do not like to remember.
Therefore, all things we like to remember are pleasant experiences.
20. Some pro-lifers are not people concerned with child welfare.
Therefore, some pro-lifers are people unconcerned with child welfare.