The 15 homes in a new development are each to be sold for one of three different prices so that the developer receives an average (arithmetic mean) of $200,000 per home. If 4 of the homes are to be sold for $170,000 each and 5 are to be sold for $200,000 each, what will be the selling price of each of the remaining 12 homes?
Choose the correct choice.
A) $200,000	B) $210,000	C) $215,000	D) $220,000	E) $230,000
IMO the answer has to be D.   5 houses are being sold for 200,000. 4 houses are being sold for $30,000 less, resulting in a loss of $120,000. To make the average selling price intact i.e. $200,000, the remaining 12 houses must be sold at such a profit that it compensates for the loss of 120,000. Hence 12x=120,000.   x=10,000.   The 12 houses are sold at $10,000 profit or at $210,000. (ANSWER $210,000)
<result>B</result>
The 15 homes in a new development are each to be sold for one of three different prices so that the developer receives an average (arithmetic mean) of $200,000 per home. If 4 of the homes are to be sold for $170,000 each and 5 are to be sold for $200,000 each, what will be the selling price of each of the remaining 12 homes?