Bunuel wrote:
Quick Sell Outlet sold a total of 40 televisions, each of which was either a Model P television or a Model Q television. Each Model P television sold for $p and each Model Q sold for $q. The average (arithmetic mean) selling price of the 40 televisions was $141. How many of the 40 televisions were Model Ptelevisions?
(average price) = (total sales)/(# of televisionssold)
\( 141 =\frac{px+q(40-x)}{40}\) , where x is the number of Model P televisions sold.
(1) The Model P televisions sold for $30 less than the Model Q televisions --> p=q-30. Not sufficient to get x.
(2) Either p=120 or q=120. Not sufficient.
(1)+(2) If q=120, then p=90, so in this case both prices would be less than the average price ($141) which is not possible. Thus p=120 and q=150. When we substitute these values we'll have only one unknown x, so we can solve for it. Sufficient.
Answer:C.
What if the value of x turns out to be non integer? My question do we make sure by solving and finding x?
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Statistics : Posted by Pankajkm • on 14 Oct 2013, 08:51 • Replies 21 • Views 73355
