Find the average of first 4 multiples of 5?  Choices:
A) 10
B) 12.5
C) 22.5
D) 31.3
E) 40.8
average = (5+10+15+20)/4= 
<gadget id="calculator">(5+10+15+20)/4</gadget>
<output>25/2 = around 12.5</output>
12.5   Answer is 12.5
<result>B</result>
Find the average of first 4 multiples of 5?