Find the average of first 4 multiples of 15? Pick one.
A) 10
B) 12.6
C) 22.5
D) 31.3
E) 37.5
average = (15+30+45+60)/4= 
<gadget id="calculator">(15+30+45+60)/4</gadget>
<output>75/2 = around 37.5</output>
37.5   Answer is 37.5
<result>E</result>
Find the average of first 4 multiples of 15?