Question

Find the indicated probability. Round to the nearest thousandth. A sample of 4 different calculators is randomly selected from a group containing 16 that are defective and 30 that have no defects. What is the probability that at least one of the calculators is defective? A)0.819 B)0.168 C)0.160 D)0.832

Answer 1

D) but I could be wrong

Answer 2

The probability of one calculator having no defects is 30/46. When a second is chosen the probability of having no defects is 29/45. The probability of no defects in the third is 28/44 and in the fourth is 27/43. 
The probability of no defects in any of the calculators is found by multiplying the individual probabilities together.


The probability of all calculators having no defects is 16.8%. The probability of at least one defect is the complement of that probability. 
ie an 83.2% probability of at least one defect.