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 6 other contributions made before john's, what is the size of his donation?
Options: A) $225 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 6 people.   so $150.   But, he also has to put in the average for himself (the seventh person), so add $75.   So $225 is your answer.   $225nswer $225
<result>A</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 6 other contributions made before john's, what is the size of his donation?