Four Cards Puzzle
We must flip card E. E is a vowel. If card E does not have an even number on the other side, the statement is not true.
We must flip card 5. If card 5 has a vowel on the other side, the statement is not true.
We must flip card N. If card N has a vowel on the other side, the statement is not true. Nothing says that each hard has one letter and one number!
We don’t need to flip card 8. Whatever card 8 has on the other side (vowel, consonant, or number), the statement is not disproven. Remember: “If a card has a vowel on one side, then it has an even number on the other side” does not mean the same thing as “If a card has an even number on one side, then it has a vowel on the other side.”
More Puzzles
Courses
Fallacy Detectors Part 1
Develop the skills to tackle logical fallacies through a series of 10 science-fiction videos with activities. Recommended for ages 8 and up.
A Statistical Odyssey
Learn about common statistical misconceptions with an interactive space adventure. Recommended for ages 12 and up.
Symbolic Logic for Teens Part 1
Learn how to make sense of complicated arguments with 14 video lessons and activities. Recommended for ages 13 and up.
Worksheets
Symbolic Logic Worksheets
Worksheets covering the basics of symbolic logic for children ages 12 and up.
Elementary School Worksheets and Lesson Plans
These lesson plans and worksheets teach students in grades 2-5 about superstitions, different perspectives, facts and opinions, the false dilemma fallacy, and probability.
Middle School Worksheets and Lesson Plans
These lesson plans and worksheets teach students in grades 5-8 about false memories, confirmation bias, Occam's razor, the strawman fallacy, and pareidolia.
High School Worksheets and Lesson Plans
These lesson plans and worksheets teach students in grades 8-12 about critical thinking, the appeal to nature fallacy, correlation versus causation, the placebo effect, and weasel words.
Statistical Shenanigans Worksheets and Lesson Plans
These lesson plans and worksheets teach students in grades 9 and up the statistical principles they need to analyze data rationally.