Hi, I am having trouble with this game theory question. I am have no solution and am stuck with the solution. Can someone please help me with the solution and explanation to it? Thank you

Game Theory Dairy farmers Luke and Stan have common access to an empty green paddock perfect for grazing cows. They go to the local cow market and must each decide independently whether to buy 10 or 20 cows. Cows cost $2000. Both Luke and Stan know that the more cows on the paddock, the less productive is each cow. With a total of 20 cows on the paddock, each cow will produce $7000 of milk in its lifetime, With a total of 30 cows on the paddock, each cow will produce $5000 of milk in its lifetime. With a total of 40 cows on the paddock, each cow will produce $4000 of milk in its lifetime. Stan Buy 10 Buy 20 $60000 Buy 10 Luke Buy 20