Union and intersection of sets
Sets, relations and functions · Mathematics
Study notes
Q: A = {1,2,3,4}, B = {3,4,5,6}. Find A ∪ B, A ∩ B. In a class, 20 like tea, 15 like coffee, 8 like both. How many like at least one? A ∪ B = {1,2,3,4,5,6}. A ∩ B = {3,4}. At least one = 20 + 15 - 8 = 27 (subtract the double-counted both).