Here’s a tip you need to know to “ace” a thinking test

“Following is an example of the kind of problems that appear on critical-thinking tests given by governmental agencies and corporations:

Assume that some Sundays are rainy and that all rainy days are boring.

           Which of the following can be logically deduced?

          (1) No clear days are boring;

          (2) some Sundays are boring; or

          (3) some Sundays are not boring.

                                           The correct answer is statement No. 2.

                     Why isn’t No. 3 also correct?

         If some Sundays are rainy, some are not rainy.

         So if some are boring, some are not boring.

         What’s wrong with my reasoning?

                                                                        Vernon Chang, Singapore

The conclusion in No. 3 doesn’t necessarily follow from the given premises.

The fact that some Sundays are rainy implies that some are not rainy.

But the fact that all rainy days are boring doesn’t imply anything about clear days. Maybe they’re all boring too. They are not, of course, but neither are all rainy days boring.

You were supposed to base your conclusion entirely on the given premises.