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- Sailors, monkey and coconuts 5 answers
You, 4 other people, and a dog are in a room. You have a bunch of tennis balls in the center of the room. When no one is looking except for the dog, you give one tennis ball to the dog and then you divide the remaining tennis balls into 5 equal piles. You take one of the piles and hide it somewhere else in the room. Each of the 4 other people in the room do this to the remaining stash of tennis balls in the center (1 for the dog, 1/5 of the remaining for them). You again give one tennis ball to the dog after all four people have done the same and divide the remaining tennis balls evenly among all 4 people and you. There are no more balls left. What is the minimum number of tennis balls that could have been in the center of the room at the beginning?