A city council will select 2 of 9 available firefighters and 1 of 6 available police officers to serve on an advisory panel. How many different groups of 3 could serve on the panel?
Choose the correct option.
A) 36  B) 72  C) 144  D) 216  E) 432
Ways to select 2 firefighters out of 9 is C29=36;   Ways to select 1 police officer out of 6 is C16=6;   Total ways to select 2 firefighters out of 9 and 1 police officer out of 6 is  36*6= 
<gadget id="calculator"> 36*6</gadget>
<output>216</output>
216.   It's called Principle of Multiplication: if one event can occur in m ways and a second can occur independently of the first in n ways, then the two events can occur in m*n ways.   Answer: 216.
<result>D</result>
A city council will select 2 of 9 available firefighters and 1 of 6 available police officers to serve on an advisory panel. How many different groups of 3 could serve on the panel?