Killer LR: 15 of the Hardest Logical Reasoning Questions of All Time Part I

Below is Part I of our discussion of the 15 hardest LSAT Logical Reasoning questions of all time. This Part contains 5 of the 15 questions, presented in chronological order. In Part II we discuss questions 6-10, and in Part III we present questions 11-15. Part IV is the finale where we discuss interesting patterns and statistics associated with these questions. This list was compiled using student practice test statistics, student question volume, and our experience teaching and writing about these questions.

Keep in mind that these questions vary in difficulty. Some questions are sly and challenging without you realizing it, while others are obviously difficult from the start. This list includes both types.

October 1994, Section 1, #24: Vinland Map Titanium Ink

Flaw in the Reasoning. This question involves titanium in both the Gutenberg Bible and the B-36 Bible. Respondents answered correctly at just 15%. Random guessing yields a 20% hit rate, so this question was statistically harder than guessing. It is considered the second hardest LSAT Logical Reasoning question ever.

December 1994, Section 1, #18: Grand Banks Cod

Must Be True. Must questions are usually not the hardest, but this one is an exception. It discusses separate estimates of cod stocks, one increasing and one decreasing by the same amount, leaving the overall estimate unchanged. The casual language in the correct answer makes it more challenging.

December 1995, Section 2, #23: Airline Seat Cancellation

Justify-PR. One of the first Justify-PR questions. Arnold and Jamie argue about an airline's moral obligation to compensate a traveler for a cancelled flight. The Principle aspect makes answers more abstract, and the correct rate was just 21%.

October 1996, Section 1, #16: Brown Dwarfs

Assumption-FL. Although there have been prior LSAT questions about brown dwarfs, this was the first and most difficult. Formal Logic makes it harder, and the science terms (brown dwarfs, red stars, hydrogen, lithium, helium) add to the difficulty.

June 1997, Section 1, #19: Meteorite Impact Crater

AssumptionX. This tricky question’s correct answer is not an assumption but is marked incorrect due to the word “more.” Many students skipped (A), the correct answer, and chose incorrectly. The science content increases the difficulty.

One final note: any such list is somewhat subjective. A question that challenges one student may not challenge another. These questions are ones students frequently ask about and that statistics and experience indicate are extremely difficult. Solving any in under two minutes is a great accomplishment.

Further reading about the Killer LSAT: Killer RC, Killer LG, Killer LR Part I, Part II, Part III, Part IV