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Discover the correct count of big, long-haired, and spotted dogs at a show by solving a puzzle using given information about the dogs' characteristics.
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Problem 1 The Dog Show
There were 150 dogs at a dog show. • Let A be the set of big dogs (over 50 pounds). • Let B be the set of dogs with long hair. • Let C be the set of dogs with spots. • 95 dogs had spots. • 8 dogs had spots and long hair and were big. • 12 dogs had only long hair. • 25 dogs had long hair and were big. • 23 dogs had only spots and were big. • 92 dogs were not big. • 49 had exactly two of these characteristics.
Long-haired Dogs Big Dogs Spotted Dogs
Long-haired Dogs Big Dogs Spotted Dogs 8 First, put the 8 big, long-haired, spotted dogs in the center!
Long-haired Dogs Big Dogs 12 8 23 Spotted Dogs Next, fill in the “only” information.
Long-haired Dogs Big Dogs 12 17 8 23 Spotted Dogs We know 25 dogs were big with long hair. There are already 8 dogs in this space – so SUBTRACT. 25-8=17
Long-haired Dogs Big Dogs 12 17 8 23 Spotted Dogs AND 49 dogs share exactly 2 of these characteristics. So far we have 40 dogs here – we need 9 more!
Long-haired Dogs Big Dogs 12 17 8 9 23 Spotted Dogs It says that 92 dogs were not big, if we add up what we have, find we are 16 short. So, there must be 16 dogs that are neither big nor spotted nor long haired. 95 dogs had spots. We have 40 so far --so we need 55 more.
Long-haired Dogs Big Dogs 12 17 8 23 9 55 Spotted Dogs 16 There are 150 dogs total. Add the rest of the dogs and subtract from 150 to find the number of big dogs.
Long-haired Dogs Big Dogs 12 17 8 23 9 55 Spotted Dogs 16 10