Answer:
2000 units
Step-by-step explanation:
We apply the contribution margin concept in solving this.
The selling price is $5
The $1000 overhead cost represents fixed costs.
The $2.50 material cost is the variable cost.
The salary of $4000 is like profits.
Bob has to sell x items to meet the break-even and attain $4000
Break-even = Fixed cost/ contribution margin per unit
fixed cost =$1000
contribution margin = Selling price - variable cost
=$5 -$ 2.50
=$2.50
break-even in units = $1000/2.50
=400 units
To achievea $ 4000 salary , Bob has to sell 400 units + $4000/2.50
=400 unit +1600 units
=2000 units