Critical Reasoning Practice Questions

1. A company claims that its new weight loss supplement leads to significant weight loss without the need for diet or exercise changes. In a clinical trial, participants who took the supplement lost an average of 10 pounds more than those who took a placebo. Which of the following is an assumption underlying the company's claim?

The participants in the trial were representative of the general population

The weight loss was due to the supplement and not other factors

The effects of the supplement are long-lasting

The supplement has no significant side effects

2. A pharmaceutical company claims that its new drug is more effective than existing treatments for a certain condition. In a clinical trial, 70% of patients who took the new drug showed improvement, compared to 60% who took a placebo. Which of the following, if true, would most weaken the company's claim?

The clinical trial had a small sample size

Some patients experienced side effects from the new drug

Existing treatments have a success rate of 75%

The improvement was measured over a short period of time

3. If it's sunny, we'll go to the beach. If we go to the beach, we'll need sunscreen. It's sunny. Therefore:

We'll go to the beach

We'll need sunscreen

Both a and b

Neither a nor b

4. A company plans to reduce its carbon footprint by switching to electric delivery vehicles. Which of the following, if true, would most weaken the effectiveness of this plan?

The initial cost of electric vehicles is higher than traditional vehicles

The electricity in the region is primarily generated from coal-fired power plants

Electric vehicles have lower maintenance costs over time

The company's competitors are also switching to electric vehicles

5. All roses are flowers. Some flowers are red. Which of the following conclusions can be logically drawn from these premises?

All roses are red

Some roses are red

No roses are red

None of the above

6. No mammals can breathe underwater. Whales are mammals. Which of the following conclusions can be logically drawn from these premises?

Whales cannot breathe underwater

Whales can hold their breath for long periods

All animals that cannot breathe underwater are mammals

Some mammals can breathe underwater

7. A study found that cities with more parks have lower crime rates. Therefore, increasing the number of parks in a city will reduce crime. Which of the following, if true, most weakens this argument?

Parks are more common in affluent neighborhoods with naturally lower crime rates

Cities with more parks tend to have larger police forces

Some parks become gathering places for criminal activity at night

The study did not account for other factors that might influence crime rates

8. A company's sales increased by 30% after it started an advertising campaign on social media. The marketing manager concludes that the social media campaign was responsible for the increase in sales. Which of the following, if true, would most weaken the marketing manager's conclusion?

The company also introduced a new product line during the same period

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

The social media campaign reached a larger audience than expected

Other companies in the same industry reported similar increases in sales without social media campaigns

9. City X has experienced a significant increase in traffic congestion over the past five years. The city council proposes building more roads to alleviate the problem. Which of the following, if true, would most strengthen the council's proposal?

Public transportation usage has increased by 20% in the same period

The population of City X has grown by 15% in the last five years

Similar cities that built more roads saw a 30% reduction in traffic congestion

The number of registered vehicles in City X has remained constant

10. A university decides to make standardized test scores optional for admission to increase diversity. Which of the following, if true, would most weaken the effectiveness of this decision?

Other universities that have made test scores optional have seen an increase in applications

Standardized tests have been criticized for cultural bias

The university's ranking has improved since making test scores optional

Students admitted without test scores have similar academic performance to those admitted with scores