Question

What is the chance of getting at least one defective item if 3 items are drawn randomly
from a lot containing 6 items of which 2 are defective item?
(b) 0.20
(d) 0.50
(c) 0.80​

Answer 1

Answer:  

(Option C) - 0.80 is the correct answer.

Given Data:

Lot containing 6 items.

2 defective items.

To Find:

Getting at least one defective item?

Step 1:

The complement of A is Not A.  

P (A) = 1 – P (Not A)  

Step 2:

P (Not A) $=\frac{4}{6} \times \frac{3}{5} \times \frac{2}{4}$

$=\frac{24}{120}$

$=\frac{1}{5}$

Step 3:

$1-\left(\frac{1}{5}\right)= \frac{4}{5}$

P (at least one defective) drawing 3 items from 6 items when 2 items defective is $\frac{4}{5}$

i.e. 0.80.