Question

A sample of 4 different calculators is randomly selected from a group containing 14 that are defective and 34 that have no defects. What is the probability that at least one of the 4 calculators in the sample is defective

Answer 1

Answer:

The answer is "0.7616".

Step-by-step explanation:

Using formula:

$\text{P( at least one de-fective) = 1 - P( all calculators work )}$

                                          $= 1-(\frac{34}{48}\times \frac{33}{47}\times \frac{32}{46}\times \frac{31}{45})\\\\= 1-(\frac{34}{1}\times \frac{11}{47}\times \frac{1}{23}\times \frac{31}{45})\\\\=1-(\frac{11594}{48647})\\\\=\frac{48647-11594}{48647}\\\\=\frac{37051}{48647}\approx 0.7616$