Over a holiday weekend, a certain car dealer sold off 4 of the cars on its lot. If the cars sold for an average of $6,000 each, how many cars were on the dealer's lot at the beginning of the weekend?(1) The average value of the remaining cars on the lot i

正确答案：B
B 解析：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.