OG详解-OG8 数学1 Q2

Choice C is correct. It’s given that 29 out of every 100 beads that the machine produces have a defect. It follows that if the machine produces k beads, then the number of beads that have a defect is 29100​​ k, for some constant k. If a bead produced by the machine will be selected at random, the probability of selecting a bead that has a defect is given by the number of beads with a defect, 29100​​ k, divided by the number of beads produced by the machine, k. Therefore, the probability of selecting a bead that has a defect is  29100k​k​​ , or  29100​​ .
Choice A is incorrect and may result from conceptual or computational errors. Choice B is incorrect and may result from conceptual or computational errors. Choice D is incorrect and may result from conceptual or computational errors.