Question

If a person invests $9,500 st 5% annual interest, how much more must be invested at 6% so that the person's annual income exceeds $1,087?

Answer 1

So need to invest more than `$10183 1/3` at 6% to earn a total in excess of $1087 interest from both accounts

Explanation:

`color(blue)("Determine original return")`
`5/100xx$9500 = $475`

`color(blue)("Determine additional investment at 6%")`

Required minimum return is `$1087`

So minimum amount extra to earn at 6% is

`6/100 x = $1086-$475`

`x=100/6xx$611`

`x=$10183 1/3` to give the exact threshold value

So need to invest more than `$10183 1/3` at 6% to earn a total in excess of $1087 interest from both accounts