Answer:
Ben must invest $1,750 as additional amount.
Explanation:
Let
"A" is the additional amount to be invested
According to given condition
Investment on 3.5% + additional Investment at 5.5% = Investment at 4.5%
($3,500 x 4%) + ( A x 5.5%) = ($3500 x 4.5%) + (A x 4.5%)
$140 + 0.055A = $157.5 + 0.045A
0.055A - 0.045A = $157.5 - $140
0.01A = $17.5
A = $17.5 / 0.01
A = $1750
Check
140 + (1750 x 5.5%) = 157.5 + (1750x4.5%)
$236.25 = $236.25