An executive invests $28,000, some at 8% and the rest at 5% annual interest. If he receives an annual return of $1,760, how much is invested at each rate?

Question

An executive invests $28,000, some at 8% and the rest at 5% annual interest. If he receives an annual return of $1,760, how much is invested at each rate?
at 8% interest	$ 
at 5% interest

R_scott · Answer

s + r = 28000 .08 s + .05 r = 1760 ... multiplying by 20 ... 1.6s + r = 35200 subtracting equations (to eliminate r) ... 0.6 s = 7200 solve for s , then substitute back to find r