Dirty Jeans?

Levi Strauss & Company estimates that a pair of jeans uses about 3,500 liters of water in its lifecycle. This includes water used in irrigating the cotton crop, stone washing the denim and laundering them at home once a week. However, the denim company claims that the water used drops to about 2,700 liters if jeans are washed half as often. By what percent does the water consumption change when jeans are washed half as often?

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