Investments Kelly has 20,000 dollar to invest. As her financial planner, you recommend that she diversify into three investments: Treasury bills that yield $5 \%$ simple interest, Treasury bonds that yield $7 \%$ simple interest, and corporate bonds that yield $10 \%$ simple interest. Kelly wishes to earn 1390 dollar per year in income. Also, Kelly wants her investment in Treasury bills to be 3000 dollar more than her investment in corporate bonds. How much money should Kelly place in each investment?