Let be the amount of money invested in loans
Let be the amount of money invested in notes
Let be the amount of money invested in bonds
Since the company invests a total of $1 million, we have:
Since the short-term loans pay annual interest at a rate of 10%, the treasury notes pay 8% interest, and the bonds pay 4% interest, and the total interest for the year is $0.06 million, we have:
Since, the company has three times as much money invested in municipal bonds as in treasury notes, we have:
Thus, we need to solve the system:
Can you use this reasoning to set up the system for the second?