If X and Y are sets of integers, X # Y denotes the set of integers that belong to set X or set Y, but not both. If X consists of 12 integers, Y consists of 18 integers, and 6 of the integers are in both X and Y, then X # Y consists of how many integers?	Pick:
A) 6
B) 16
C) 18
D) 30
E) 174
The number of integers that belong to set X ONLY is 12-6= 
<gadget id="calculator">12-6</gadget>
<output>6</output>
6;   The number of integers that belong to set Y ONLY is   18-6= 
<gadget id="calculator">  18-6</gadget>
<output>12</output>
12;   The number of integers that belong to set X or set Y, but not both is   6+12= 
<gadget id="calculator">  6+12</gadget>
<output>18</output>
18.   Answer: 18.
<result>C</result>
If X and Y are sets of integers, X # Y denotes the set of integers that belong to set X or set Y, but not both. If X consists of 12 integers, Y consists of 18 integers, and 6 of the integers are in both X and Y, then X # Y consists of how many integers?