Question

Cowboy Bob owns a used car lot. There are currently 40 cars on his lot, and the mean weight of those cars is 3,200 pounds. Cowboy Bob sells 5 of the cars, and the mean weight of the remaining cars is then 3,100 pounds. What is the mean weight, in pounds, of the 5 cars that were sold?

A. 3,100 pounds

B. 3,200 pounds

C. 3,000 pounds

D. 3,020 pounds

Answer 1

The mean weight of the 5 cars sold by Cowboy Bob is calculated by finding the total weight of all 40 cars, subtracting the total weight of the remaining 35 cars, and then dividing the result by 5. The mean weight of the 5 sold cars is 3,900 pounds, which is not listed among the provided options.

Step-by-step explanation:

To find the mean weight of the 5 cars that Cowboy Bob sold, we first calculate the total weight of all 40 cars and then subtract the total weight of the remaining 35 cars after the 5 were sold.

The total weight of the 40 cars is 40 cars × 3,200 pounds/car = 128,000 pounds. After selling 5 cars, the mean weight of the remaining 35 cars is 3,100 pounds/car. So the total weight of these 35 cars is 35 cars × 3,100 pounds/car = 108,500 pounds.

To find the total weight of the 5 sold cars, we subtract the weight of the remaining cars from the original total weight: 128,000 pounds - 108,500 pounds = 19,500 pounds.

Finally, to find the mean weight of the 5 sold cars, we divide the total weight of the sold cars by 5:

19,500 pounds ÷ 5 cars = 3,900 pounds.

Since 3,900 pounds is not one of the options provided, let's check the calculation step by step:

1. Total weight of 40 cars: 40 × 3,200 = 128,000 pounds.
2. Total weight of 35 cars: 35 × 3,100 = 108,500 pounds.
3. Total weight of 5 sold cars: 128,000 - 108,500 = 19,500 pounds.
4. Mean weight of 5 sold cars: 19,500 ÷ 5 = 3,900 pounds.

Unfortunately, the provided options A, B, C, and D do not include 3,900 pounds. Therefore, the mean weight of the 5 cars sold by Cowboy Bob is 3,900 pounds, not one of the options given.