A man invests $6000 in two accounts. The first account pays 5% simple interest and the second pays 8.5% simple interest. Together the investments earn $370 per year. How much of the $6000 is invested at 5%?

Question

A man invests $6000 in two accounts.  The first account pays 5% simple interest and the second pays 8.5% simple interest.  Together the investments earn $370 per year.  How much of the $6000 is invested at 5%?

anonymous · Answer

let A be the amount invested at 1st account and B amount invested in 2nd account.
now we have equations:

(1) A+B=6000 [because sums invested in both account is $6000]
(2) (5/100)*A + (8.5/100)*B = 370 [because he earn $370 from both accounts]

solve the equations, substitute B from (1) into (2), you can get A. which is the anwer required.