Rob and Beth are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of holiday wrapping paper. Rob sold 10 rolls of plain wrapping
paper and 17 rolls of holiday wrapping paper for a total of $341. Beth sold 16 rolls of plain
wrapping paper and 14 rolls of holiday wrapping paper for a total of $374. Find the cost of one
roll of plain wrapping paper.