A tea estate has available 500 acres of land and they need to pick the tea leaves either using a traditional machine or modern machine. For each acre of land, the traditional machine can pick 30 kg of tea leaves, creates 10 kg of waste, and requires 20 liters of fuel. For each acre of land, the modern machine can pick 40 kg of tea leaves, creates 15 kg of waste, and requires 15 liters of fuel. The estate has available 9000 liters of fuel can handle at most 6000 kg of waste. For how many acres should each machine be used to maximize the amount of tea leaves that can be picked?