OG详解-OG9 数学1 Q18

Choice D is correct. It’s given that a hose puts 88x ounces of water in a bucket in 5y minutes. Therefore, the rate at which the hose puts water in the bucket, in ounces per minute, can be represented by the expression 88x5y​​. Let w represent the number of ounces of water the hose puts in the bucket in 9y minutes at this rate. It follows that the rate at which the hose puts water in the bucket, in ounces per minute, can be represented by the expression  w9​y​. The expressions 88x5y​​ and w9​y​ represent the same rate, so it follows that  88x5y​=w9y​​. Multiplying both sides of this equation by 9y yields 792xy​5y​= w, or 792​x5​= w. Therefore, the number of ounces of water the hose puts in the bucket in 9y minutes can be represented by the expression 792x5​​ .
Choice A is incorrect and may result from conceptual or calculation errors. Choice B is incorrect and may result from conceptual or calculation errors. Choice C is incorrect and may result from conceptual or calculation errors.