Problema Solution

Tina invested $600, part at 8% interest per year, and the rest at 12% interest per year. At the end of the year, the total interest was $56. How much did she invest at each rate?

Answer provided by our tutors

.08x + .12(600 - x) = 56

.08x + 72 - .12x = 56

-.04x + 72 = 56

-.04x = -16

x = 400

Therefore, she invested $400 at 8% and $200 at 12%.