Q
In May, Xiang sold 15 used cars. For these cars the rang of selling prices was 15,000 and the lowest selling price was 4,500. IN June, Xiang sold 10 cars. For these 10 cars, the range of the selling price was 16,500 and the lowest selling price was 6,100. What is the range of selling price of the 25 used cars sold by Xiang in May and June?
15,600 15,750 16,820 18,100 19,200

The Formal answer is:
Lowest Price is 4,500 (agree with)
Highest price is 6,100 + 16,500 = 22,600 (disagee with)
Range is 22,600 - 4,500 = 18,100 (disagree with)

My Answer:
Why isn't the answer 16,500 - 4,500 = 12,000? It does not make sence to me to add the 6,100.