Given statement (1) alone, we only know average values of both the cars that were sold and
the cars that remained; the dealer could have sold 4 cars and had 1 left, or sold 8 cars and had 2
left, or an infinite number of other options. So we can eliminate A and D.
With statement (2), we are able to find the number of cars sold by dividing the total sales by the
average price. 48,000/6,000 = 8, so the dealer sold 8 cars. Since that is 4/5 of the cars on the lot,
the dealer started off with 10 cars. Statement (2) is sufficient, so the answer is B.