Given the cost function and the revenue function , find the profit function .
A ticket to the zoo costs $15 for children and $30 for adults. On a certain day, total attendance at the zoo was 2,000 persons and total gate revenue was $37,500. How many children bought tickets on that day?
Noah, Matthew, and Ethan opened a grocery store. They invested 14,000 LE, 4,000 LE, and 12,000 LE respectively. At the end of the year, the profit was 18,900 LE. If of the profit was paid as taxes, was kept as reserve, and the remainder was shared among them according to the ratio of their investments, determine each person’s profit.