Final answer:
The cost of one roll of plain wrapping paper and one roll of shiny wrapping paper is $12 each. This was determined by setting up a system of equations based on the sales made by Eugene and Jill and solving for the prices.
Step-by-step explanation:
To find the cost of one roll of plain wrapping paper and one roll of shiny wrapping paper, we can set up a system of equations based on the information given about Eugene's and Jill's sales:
- Eugene sold 3 rolls of plain wrapping paper and 11 rolls of shiny wrapping paper for $168.
- Jill sold 10 rolls of plain wrapping paper and 11 rolls of shiny wrapping paper for $252.
Let's define two variables:
We can then write two equations:
- 3x + 11y = 168 (Eugene's sales)
- 10x + 11y = 252 (Jill's sales)
To solve for x and y, we can subtract the first equation from the second equation to eliminate y:
10x + 11y - (3x + 11y) = 252 - 168
7x = 84
x = 12
Now that we have the cost of one roll of plain wrapping paper ($12), we can substitute it back into either equation to find y, the cost of one roll of shiny wrapping paper. Let's use the first equation:
3(12) + 11y = 168
36 + 11y = 168
11y = 132
y = 12
Thus, one roll of plain wrapping paper costs $12 and one roll of shiny wrapping paper also costs $12.