Answer and Explanation:
The computation of the extra profit above the current level is shown below:
Volume New 10,000 units Old 7,500 units 
Selling Price $57,500 $46,875
 (10,000 × $5.75) (7,500 × $6.25) 
Less: 
Variable cost at $1.55 ($15,500) ($11,625)
 (10,000 × $1.55) (7,500 × $1.55) 
Less: 
Fixed Cost ($12,000) ($12,000) 
Profit $30,000 $23,250
As it can be seen that there is an extra profit of $6,750
= $30,000 - $23,250
= $6,750
So, the company should able to reduce the selling price per unit at 10,000 units 
Here profit formula is 
Profit = Sales - variable cost - fixed cost