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MathNet 2013 Question 66

Math Olympiad Vault · MathNet 2013

Question 66

In Trocalândia, $20\%$ of the cats think they are dogs and $25\%$ of the dogs think they are cats. One day a veterinary psychologist tests all the cats and dogs in Trocalândia and finds that $30\%$ of the total think they are cats. What proportion of the animals tested are dogs?