CCTST Deductive Reasoning 3

Question 1

Some cats are black. All black animals are visible at night with special goggles. Which statement must be true?

Accepted Answer

Some cats are visible at night with special goggles

Answer

The black cats (a subset of cats) are all visible at night, so some cats must be visible.

Question 2

If you score above 90, you earn an A. If you earn an A, you are exempt from the final. Darnell scored 95. What follows?

Accepted Answer

Darnell is exempt from the final

Answer

95 > 90 triggers the first rule (A grade), which triggers the second rule (final exemption) via chained modus ponens.

Question 3

All squares are rectangles. Figure X is not a rectangle. What can be concluded about Figure X?

Accepted Answer

Figure X is not a square

Answer

Since being a rectangle is necessary for being a square, a non-rectangle cannot be a square.

Question 4

No professors are undergraduates. Some students are undergraduates. What must be true?

Accepted Answer

Some students are not professors

Answer

The undergraduates among students cannot be professors, so at least some students are not professors.

Question 5

If the hypothesis is false, the experiment is invalid. The experiment is valid. What follows?

Accepted Answer

The hypothesis is true

Answer

By modus tollens, a valid experiment (not invalid) implies the hypothesis is not false (i.e., true).

(CCTST) California Critical Thinking Skills Test Practice Test