Final answer:
The farmer initially had 220 bushels of corn. After selling 16 3/4 bushels a day for 6 days (a total of 100 1/2 bushels), the farmer's supply decreased to 119 1/2 bushels. Therefore, the change in the number of bushels the farmer has for sale is -100 1/2 bushels.
Step-by-step explanation:
To answer this question, we first need to calculate how many bushels the farmer sells each day for 6 days. The farmer sells an average of 16 3/4 bushels a day, so for 6 days, we multiply 16 3/4 by 6, which gives us 100 1/2 bushels.
We then subtract this quantity from the total number of bushels the farmer initially had, which is 220 bushels. So, 220 bushels minus 100 1/2 bushels leaves the farmer with 119 1/2 bushels.
The change in the number of bushels the farmer has for sale is therefore: 220 (initial quantity) minus 119 1/2 (remaining quantity), which equals 100 1/2 bushels. We note this change as a negative number because it is a decrease, so the signed number representing the change is -100 1/2 bushels.
Learn more about Multiplication and Subtraction