Question 810925
If ben invests $4000 at 4% interest per year, how much additional money must he invest at 5 ½% annual interest to ensure the interest he receives each year is 4 ½% of the total amount invested?
:
the equation
let x = amt required at 5.5%
.055x + .04(4000) = .045(x+4000)
.055x + 160 = .045(x+4000)
.055x + 160 = .045x + 180
.055x - .045x = 180 - 160
.01x = 20
x = 20/.01
x = $2000 invested at 5.5%
:
:
Check this
.045(2000+4000) = 270
.055(2000) + .04(4000) = 270