Problema Solution

Select the set of equations that represents the following situation: Mike invested $240 for one year. He invested part of it at 9% and the rest at 10%. At the end of the year he earned $23.42 in interest. How much did Mike invest at each rate of interest?

Answer provided by our tutors

Set up the equation:

0.09x + 0.1(240-x) = 23.42

Solve for x 

x = 58

he invested $58 at 9%

he invested $182 at 10%