P(ALL 3 units work) = P(1st unit works AND 2nd unit works AND 3rd unit works)A machine produces 10 units of an article in a day of which 4 are defective. The quality inspector allows releases of the products if he finds none of the 3 units chosen by him at random to be defective. What is the probability of quality inspector allowing the release?
a) 1/5
b) 6/10
c) 4/10
d) 1/6
e) 5/6
= P(1st unit works) x P(2nd unit works) x P(3rd unit works)
= 6/10 x 5/9 x 4/8
= [spoiler]1/6[/spoiler]
= D
RELATED RESOURCE:
- Probability of Event A AND Event B: https://www.gmatprepnow.com/module/gmat ... /video/750
Cheers,
Brent
