Question 481029

given:

A total of {{{10000}}} is invested in two funds paying {{{5}}}%={{{.05}}} and {{{7}}}%={{{.07}}} annual interest

the combined annual interest is ${{{630}}}

solution:

{{{.07x+.05(10000-x)=630}}}


{{{.07x+500-.05x=630}}}


{{{.02x=630-500}}}


{{{.02x=130}}}


{{{x=130/.02}}}


{{{x=6500}}} invested at {{{7}}}% interest rate


thus the remaining {{{10000-6500=3500}}} invested at {{{5}}}% interest rate


check:


{{{.07*6500+.05*3500=630}}}


{{{455+175=630}}}


{{{630=630}}}