If the operation € is defined for all x and y by the equation x € y = 2*x*y, then 7 € (4 € 5) = Pick.
A) 80
B) 120
C) 160
D) 240
E) 560
working inside out,   (4 € 5) = 2*4*5= 
<gadget id="calculator">2*4*5</gadget>
<output>40</output>
40   7 € 40= 2*3*40 = 560   Hence, answer is 560
<result>E</result>
If the operation € is defined for all x and y by the equation x € y = 2*x*y, then 7 € (4 € 5) =