Answer:
 46.44%
Step-by-step explanation:
The computation of the percentage earned on the investment is shown below:
But before that the profit is 
Profit = Sale - Commissions - (Cost + Commissions) + Dividends 
= ($120 × 100) - $75 - (($85 × 100) + $75) + ($4 × 100) 
= $12,000 - $75 - ($8,500 + $75) + $400 
= $3,750 
 Now 
Percentage earned on investor's funds is 
= $3,750 ÷ $8,075 
= 46.44%