A factory makes 9 -inch, 7 -inch, and 4 -inch concrete screws. During a certain day, the number of 9

Question

A factory makes 9 -inch, 7 -inch, and 4 -inch concrete screws. During a certain day, the number of 9 -inch concrete screws that the factory makes is 5 times the number n of 7 -inch concrete screws, and the number of 4 -inch concrete screws is 22 . During this day, the factory makes 100 concrete screws total. Which equation represents this situation?

Accepted Answer

Choice D is correct. It's given that during a certain day at a factory, the number of 7 -inch concrete screws the factory makes is n and the number of 4 -inch concrete screws the factory makes is 22 . It's also given that during this day the number of 9 -inch concrete screws the factory makes is 5 times the number of 7 -inch concrete screws, or 5 n . Therefore, the total number of 7 -inch, 9 -inch, and 4 -inch concrete screws is n + 5 n + 22 , or 6 n + 22 . It's given that during this day, the factory makes 100 concrete screws total. Thus, the equation 6 n + 22 = 100 represents this situation. Choice A is incorrect. This equation represents a situation where the total length, in inches, of all the concrete screws, rather than the total number of concrete screws, is 100 . Choice B is incorrect and may result from conceptual or calculation errors. Choice C is incorrect. This equation represents a situation where the total number of 9 -inch concrete screws and 4 -inch concrete screws, not including the 7 -inch concrete screws, is 100 .

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