Which one of the following numbers can be removed from the set S = {0, 2, 4, 5, 9} without changing the average of set S? Choose the correct choice from the following options.
A) 0  B) 2  C) 4  D) 5  E) 6
Solution:   The average of the elements in the original set S is: (0+2+4+5+9) /5 =20 /5= 
<gadget id="calculator">20 /5</gadget>
<output>4</output>
4.   If we remove an element that equals the average, then the average of the new set will remain unchanged. The new set after removing 4 is {0, 2, 5, 9}.   The average of the elements is,   (0+2+5+9) /4=16 /4= 
<gadget id="calculator">16 /4</gadget>
<output>4</output>
4.   Answer: Option 4
<result>C</result>
Which one of the following numbers can be removed from the set S = {0, 2, 4, 5, 9} without changing the average of set S?