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UKMT Senior Kangaroo, 2020

Algebra Difficulty 3.0 AMC 10/12 Prove it United Kingdom

On an island, kangaroos are always either grey or red. One day, the number of grey kangaroos increased by $28\%$ while the number of red kangaroos decreased by $28\%$ . The ratios of the two types of kangaroos were exactly reversed. By what percentage did the total number of kangaroos change?

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