Problema Solution

You invested $13,000 in two accounts paying 5% and 7% annual interest, respectively. If the total interest earned for the year was $850, how much was invested at each rate?

Answer provided by our tutors

Let $x be invested at 5% interest and rest of the amount $(13000-x) be invested at 7% interest.

After one year total interest will be

=5x/100 + 7(13000-x)/100 = (91000-2x)/100

By the given condition of the problem,

(91000-2x)/100=850

or, 91000-2x = 85000

or, 2x=6000

or, x = 3000

He should invest $3000 at 5% interest and $(13000-3000)=$10000 at 7% interest.