The average (arithmetic mean) of 20, 40, and 60 is 9 more than the average of 10, 70, and what number? Choose the most appropriate option.
A) 15	B) 25	C) 35	D) 13	E) 55
a1 = 120/3= 
<gadget id="calculator">120/3</gadget>
<output>40</output>
40   a2= a1 -9 = 31   sum of second list = 31*3= 
<gadget id="calculator">31*3</gadget>
<output>93</output>
93   therefore the number= 93 -80= 
<gadget id="calculator">93 -80</gadget>
<output>13</output>
13   ANSWER:13
<result>D</result>
The average (arithmetic mean) of 20, 40, and 60 is 9 more than the average of 10, 70, and what number?