if john makes a contribution to a charity fund at school, the average contribution size will increase by 50 % reaching $ 75 per person. if there were 4 other contributions made before john ' s, what is the size of his donation?	Select.
A) $ 100  B) $ 175  C) $ 200  D) $ 250  E) $ 450
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">5 * 75</gadget>
<output>375</output>

<gadget id="calculator">5 * 50</gadget>
<output>250</output>

<gadget id="calculator">375 - 250</gadget>
<output>125</output>

<gadget id="calculator">125 + 50</gadget>
<output>175</output>

<result>B</result>
if john makes a contribution to a charity fund at school, the average contribution size will increase by 50 % reaching $ 75 per person. if there were 4 other contributions made before john ' s, what is the size of his donation?
add(subtract(multiply(add(4, const_1), 75), multiply(add(4, const_1), 50)), 50)
cavg = average contribution before john cavg * 1.5 = 75 , therefore the average cont is $ 50 before john . if he needs to increase the average contribution by $ 25 , he must put in $ 25 for each of the 4 people . so $ 100 . but , he also has to put in the average for himself ( the fiveth person ) , so add $ 75 . so $ 175 is your answer . answer b