Question 1183692
A lot consists of 20 defective and 80 non-defective items from which two items
are chosen without replacement. Events A & B are defined as A = the first item
chosen is defective, B = the second item chosen is defective
a.	What is the probability that both items are defective?<pre>
(20/100)(19/99) = 19/495 = 0.038383838... = 3.8383...%</pre>
b.	What is the probability that the second item is defective<pre>
(20/100)(19/99)+(80/100)(20/99) = 1/5 = 0.2 = 20%


What's interesting here, that Ikleyn missed, is that if we drew n items,
where n =1,2,...,100 the probability that the nth item drawn is defective is
always 1/5 or 20%. 
 
Edwin</pre>