When the test-makers are creating questions for the LSAT, they have a vast array of “weapons” with which to attack. They can create sophisticated stimuli, complicated questions, and cleverly appealing incorrect answer choices. A more specific example is their use of numbers and percentages; as discussed in our PowerScore Logical Reasoning Bible, the test-makers prey upon several common misunderstandings about what can be gleaned from limited data.
Many people find it somewhat counter-intuitive that a company with a sharply declining market share could at the same time be seeing profits on the rise. But, as discussed in the LRB, a rising percentage isn’t necessarily associated with increasing numbers, and a decreasing percentage is not always associated with a decrease in the bottom line figure (for more on numbers, percentages, and the many other ways that Logical Reasoning questions are constructed to be difficult, see the discussion in the Logical Reasoning Bible Chapter 17. For practice with Logical Reasoning concepts, check out our Logical Reasoning Workbook).
The test-makers like to include Logical Reasoning questions that deal with numbers because they know that LSAT students are not necessarily as adept with numbers as their GMAT counterparts. And when a group of numbers is listed, one after another, that can really throw a lot people off track. In one example, a therapist points out that behavioral therapy sessions were able to solve 75% of the 60 problems studied within 50 weeks, supposedly proving 50 weeks sufficient to solve over 50% of such problems (that is, the majority). Even just keeping track of all of those numbers is something of a challenge, before you can get conclude that this flawed reasoning fails to consider the possibility that any given one of those 60 problems might affect a majority of the population.
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