EduFarming
Your list · 0हिं

Type at least two letters. Press Esc to close.

↑↓ navigate↵ openTAB cycle filter

Conditional Probability & Bayes' Theorem · Question 95 of 125

Question 95

HardOriginal question

Machines A, B and C make 50%, 30% and 20% of a factory's bolts, and 1%, 2% and 3% of their bolts are faulty. What is the probability that a bolt picked at random is faulty?

Options for question 95

Show the answer and explanation
CorrectNot quiteAnswer B

Correct answer: B

Explanation

  1. 0.5×0.01+0.3×0.02+0.2×0.030.5 \times 0.01 + 0.3 \times 0.02 + 0.2 \times 0.03.

  2. 0.005+0.006+0.006=0.0170.005 + 0.006 + 0.006 = 0.017.

Worth noting

0.02 averages the three fault rates as if each machine made a third of the bolts.

Concept
The theorem of total probability
Typical time
120 s
Your time
—
The rule this testsThe theorem of total probability
Practise this chapter →

Ten questions from Conditional Probability & Bayes' Theorem, at your own pace.

Practise this chapter →

Ten questions from Conditional Probability & Bayes' Theorem, at your own pace.

Practise this chapterAll 125 questions in Conditional Probability & Bayes' TheoremRevise the notes for Conditional Probability & Bayes' Theorem