A box in a supply room contains 21 compact fluorescent lightbulbs, of which 7 are rated 13-watt, 9 are rated 18-watt, and 5 are rated 23-watt. Suppose that three of these bulbs are randomly selected. (Round your answers to three decimal places.) (a) What is the probability that exactly two of the selected bulbs are rated 23-watt? (b) What is the probability that all three of the bulbs have the same rating? (c) What is the probability that one bulb of each type is selected?

A box in a supply room contains 21 compact fluorescent lightbulbs, of which 7 are rated 13-watt, 9 are rated 18-watt, and 5 are rated 23-watt. Suppose that three of these bulbs are randomly selected. (Round your answers to three decimal places.) (a) What is the probability that exactly two of the selected bulbs are rated 23-watt? (b) What is the probability that all three of the bulbs have the same rating? (c) What is the probability that one bulb of each type is selected?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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. Assume that 75 percent of the students at the university have taken 4 years of high school math. Of those with four years of high school math, 80 percent plan to major in science. Of those without 4 years, only 10 percent plan to major in science. You stop a student at random. If the student plans to major in science, what is the probability that this student had four years of high school math?
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