Mathematics
posted by Anonymous .
Carletta has $10,000 to invest. As her financial consultant you recommend that she invest in Treasury Bills that yield 6%, Treasury Bonds that yield 7%, and coroporate bonds that yield 8%. Carletta wants to have an annual income of $680, and the amount invested in corporate bonds must be half that invested in Treasury Bills. Find the equations.

Bills + Bonds + Corporate=10000
Bills + Bonds + 1/2 Bills=10000
That is equation 1)
Bills(.06)+ bonds(.07) + corporate(.08)=680
Bills*.06 + bonds*.07 +1/2 bills*.08=680 or equation 2)
1.5*bills(.06) + bonds(.07)=680
So now you have two equations, two unknowns, and you can solve.