Question

In a shipment of 20 computers, 3 are defective. Three computers are randomly selected and tested. What is the probability that all three are defective if the first and second ones are not replaced after being tested? (1/1140)

Please help me to answer this question. This question is under of topic basic and rule probability. I hope one of you guys can come up with a complete answer.​

Answer 1

a. 1/760

b.1/1140

c.27/8000

d.3/5000

I chose D, is this correct

Explanation: