The average of 20, 40 and 180 is twice the average of 10, 30, and which of the following ?
Select:
A) 1)10	B) 2)30	C) 3)60	D) 4)80	E) 5)180
20 40 180 = 180+60= 
<gadget id="calculator">180+60</gadget>
<output>240</output>
240/3= 
<gadget id="calculator">240/3</gadget>
<output>80</output>
80.   80/2= 
<gadget id="calculator">80/2</gadget>
<output>40</output>
40   10 30 x= 40+x/3 should be smaller than 40   cross multiply 40*3-40= 
<gadget id="calculator">40*3-40</gadget>
<output>80</output>
80   4)80
<result>D</result>
The average of 20, 40 and 180 is twice the average of 10, 30, and which of the following ?