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 3 other contributions made before john's, what is the size of his donation?	Choose one:
A) $100  B) $150  C) $200  D) $250  E) $450
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 3 people.   so $75.   But, he also has to put in the average for himself (the fourth person), so add $75.   So $150 is your answer.   Answer $150
<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 3 other contributions made before john's, what is the size of his donation?