Deductive Reasoning Practice

All mammals are warm-blooded animals.

A dog is a mammal.

Therefore, a dog is a warm-blooded animal.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.6.1

CCSS.RI.6.8

CCSS.RI.7.8

CCSS.RI.8.1

CCSS.RI.8.8

No fish can fly.

A salmon is a fish.

Therefore, a salmon cannot fly.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.6.1

CCSS.RI.6.8

CCSS.RI.8.1

CCSS.RI.8.8

CCSS.RL.8.1

Some students are good at math.

John is a student.

Therefore, John is good at math.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.7.1

CCSS.RI.7.8

CCSS.RI.8.8

CCSS.RL.7.1

CCSS.RL.8.1

All cats are good swimmers.

My pet dog is a cat.

Therefore, my pet dog is a good swimmer.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.6.8

CCSS.RI.7.1

CCSS.RI.7.8

CCSS.RI.8.1

CCSS.RL.6.1

All roses are flowers.

Some beautiful plants are flowers.

Therefore, some beautiful plants are roses.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.6.8

CCSS.RI.7.8

CCSS.RI.8.1

CCSS.RL.6.1

CCSS.RL.8.1

If it rains, the ground gets wet.

It is raining.

Therefore, the ground is getting wet.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.7.1

CCSS.RI.7.8

CCSS.RI.8.1

CCSS.RI.8.8

CCSS.RL.6.1

Many people like chocolate.

Sarah is a person.

Therefore, Sarah likes chocolate.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.7.1

CCSS.RI.7.8

CCSS.RI.8.1

CCSS.RL.6.1

CCSS.RL.7.1

All triangles have four sides.

This shape is a triangle.

Therefore, this shape has four sides.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.6.8

CCSS.RI.7.1

CCSS.RI.8.1

CCSS.RL.7.1

CCSS.RL.8.1

Some doctors are rich.

Some rich people are happy.

Therefore, some doctors are happy.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.6.1

CCSS.RI.6.8

CCSS.RI.8.8

CCSS.RL.6.1

CCSS.RL.7.1

All professional athletes train hard.

Michael Jordan was a professional athlete.

Therefore, Michael Jordan trained hard.

• Valid (logical): IF the premises are true, the conclusion MUST be true

• Sound: Valid AND the premises are actually true

• Invalid (illogical): Possible for the premises to be true and conclusion false

Tags

CCSS.RI.7.1

CCSS.RI.7.8

CCSS.RI.8.8

CCSS.RL.6.1

CCSS.RL.7.1