If 2a – b = 3c, where a, b, and c are non-zero integers, which of the following could be the average (arithmetic mean) of a and b, if the average must itself be an integer?	Select the correct option:
A) -2  B) -1  C) 1  D) 10  E) 12
Let's say Average of a &amp; b is c   a+b/2=c   a+b= 2c   2a-b=3c   a+b=2c   --------   3a = 5c   a=5c/3   we can plug in all answer choices for average - " c " and see which one gives us an integer as "a" is also an integer.   5(-2)/3 = -10/3   5(-1)/3 = -5/3   5(1)/3 = 5/3   5(10)/3 = 50/3   5(12)/3 = 60/3= 
<gadget id="calculator">60/3</gadget>
<output>20</output>
20 ( Hence 12 is the correct answer)   ANSW12R:12
<result>E</result>
If 2a – b = 3c, where a, b, and c are non-zero integers, which of the following could be the average (arithmetic mean) of a and b, if the average must itself be an integer?