medium · LSAT Logical Reasoning

A scientist observes that whenever a certain chemical is present in a lake, the fish population declines. She concludes that the chemical is toxic to the fish.

Which one of the following, if true, most weakens the scientist's conclusion?

  1. The chemical is a byproduct of an algae species that blooms only when water temperatures climb to levels independently fatal to fish
  2. Other researchers studying separate species have shown the chemical to be entirely harmless to lake-dwelling birds and to mammals alike
  3. The chemical also appears, though at markedly lower concentrations, in several nearby lakes whose fish populations remain stable
  4. The decline in fish was distinctly steeper along the lake's colder northern shore than along its warmer southern shoreline alone
  5. The chemical breaks down completely within a few short weeks of first entering the water and leaves behind no lasting residue

Sign up free to see the explanation and track your rank →

More LSAT Logical Reasoning practice

KomFi: Test Prep Made Easy

KomFi: Test Prep Made Easy — free adaptive practice for GMAT, GRE, SAT, ACT, National Real Estate Exam, Investment Banking, and finance with full explanations.

KomFi Academy is free GMAT prep and personalized GMAT help built as a training platform: 75,000+ practice questions, 26,500+ flashcards, on-demand video lectures, podcasts, and 4K slide decks. Flagship tracks: Free GMAT Prep, Free GMAT Resources, National Real Estate Exam Prep, Investment Banking Prep, Finance Prep, GRE, SAT, ACT, LSAT, MCAT, Financial Accounting, Private Equity, Private Credit, and Quantitative Finance.

Free GMAT Prep & Personalized GMAT Help

What's inside

Topics

View pricing · Read testimonials