Assumption and Conclusion Reasoning Questions

1. All dolphins are mammals. Some mammals live in water. Therefore, some dolphins live in water. This argument is:

Valid

Sound

Invalid

Both valid and sound

2. If it's raining, the ground is wet. The ground is wet. Therefore, it must be raining. This reasoning is:

Deductive

Inductive

Abductive

Fallacious

3. A company introduces a new product and sees a spike in sales. The CEO concludes that the new product is responsible for the increase in revenue. Which of the following, if true, would most weaken this conclusion?

The company launched a major advertising campaign at the same time

The new product is priced higher than similar products in the market

Customer reviews of the new product are mostly positive

The company's main competitor recently went out of business

4. A company's sales have increased by 20% since it started advertising on social media. The marketing manager concludes that social media advertising is highly effective. Which of the following, if true, would most weaken this conclusion?

The company's main competitor went out of business during the same period

The company's product quality improved significantly in the same timeframe

Other companies in the industry have seen similar sales increases without social media advertising

The cost of social media advertising is much lower than traditional advertising methods

5. A study finds that students who eat breakfast perform better on morning tests. The researchers conclude that eating breakfast improves cognitive function. Which of the following is an assumption made in this conclusion?

All students have access to nutritious breakfast options

The improved performance is due to breakfast and not other morning routines

Students who skip breakfast are less intelligent

Eating breakfast is the most important meal of the day

6. If it rains, the picnic will be canceled. The picnic was not canceled. Therefore, it did not rain. This argument is an example of:

Modus ponens

Modus tollens

Affirming the consequent

Denying the antecedent

7. No reptiles have fur. Some animals have fur. Therefore, some animals are not reptiles. This argument is:

Valid

Sound

Invalid

Both valid and sound

8. A study shows that people who eat breakfast regularly have lower rates of obesity. Therefore, eating breakfast helps prevent weight gain. Which of the following is an assumption underlying this conclusion?

All obese people skip breakfast

Eating breakfast increases metabolism

There are no other factors influencing obesity rates

Breakfast-eaters have similar lifestyles to non-breakfast-eaters

9. All metals conduct electricity. This material conducts electricity. Therefore, this material is a metal. This argument is:

Valid

Sound

Invalid

Both valid and sound

10. All birds lay eggs. Penguins lay eggs. Therefore, penguins are birds. This argument is:

Valid

Sound

Invalid

Both valid and sound