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A box contains 16 transistors, 3 of which are defective. If 3 are selected at random, find the probability of the statements below.a. All are defectiveb. None are defectiveWith, and without replacement

User Robbyt
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1 Answer

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Given 16 transistors, 3 of which are defective, 13 are not defective

Part A: All are defective.

With replacement


\begin{gathered} P=(3)/(16)\cdot(3)/(16)\cdot(3)/(16) \\ P=(27)/(4096) \\ \\ \text{The probability that all are defective with replacement is }(27)/(4096) \end{gathered}

Without replacement


\begin{gathered} P=(3)/(16)\cdot(2)/(15)\cdot(1)/(14) \\ P=(143)/(280) \\ \\ \text{The probability that all are defective without replacement is }(1)/(560) \end{gathered}

Part B: None are defective

With replacement


\begin{gathered} P=(13)/(16)\cdot(13)/(16)\cdot(13)/(16) \\ P=(2197)/(4096) \\ \\ \text{Therefore, the probability that none are defective with replacement is }(2197)/(4096) \end{gathered}

Without replacement


\begin{gathered} P=(13)/(16)\cdot(12)/(15)\cdot(11)/(14) \\ P=(143)/(280) \\ \\ \text{Therefore, the probability that none are defective without replacement is }(143)/(280) \end{gathered}

User Brookes
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