TradingCo wants to invest at most $10,000 in 2021. Two investment options are proposed: KTS and DB, with annual yields of 20% and 10% respectively. Based on market research, TradingCo wishes to limit the amount invested in KTS to no more than 60% of the total investment. How should TradingCo invest to generate the highest annual yield? Develop an LP model that represents the problem. Please clearly state decision variables, objective and constraints.