<PRE><B>Question 1116033</B>
In a shipment of 22 smart phones, 3 are defective. How many ways can a quality control inspector randomly test 5 smart phones, of which 3 are defective? 
I tried doing C(5,3) and P(5,3). Neither are correct. It says the answer is 171. I really don&#39;t know what I&#39;m doing wrong. Thanks in advance. 
----
If 3 of the 5 are defective, only 2 are selected from the 19 that
are not defective.
Ans: 19C2 = (19*18)/(1*2) = 19*9 = 171
-------------
Cheers,
Stan H.
------------</PRE>