If the operation € is defined for all x and y by the equation x € y = 3*x*y, then 3 € (4 € 5) =
Answers:
A) 80 B) 120 C) 160 D) 540 E) 660
working inside out,   (4 € 5) = 3*4*5= 
<gadget id="calculator">3*4*5</gadget>
<output>60</output>
60   3 € 60= 3*3*60= 
<gadget id="calculator">3*3*60</gadget>
<output>540</output>
540   Hence, answer is 540
<result>D</result>
If the operation € is defined for all x and y by the equation x € y = 3*x*y, then 3 € (4 € 5) =