Answer:
The break-even point in units for ordinary laptops is 2,100 units.
Explanation:
Contribution Margin per unit (ordinary) = Selling Price - Variable cost
                                 = $650 -$605
                                 = $45
Contribution Margin per unit (premium) = Selling Price - Variable cost                     = $1,150 -$1,090
= $60
$45* 4x + $60x = Fixed Costs = $126,000
= 180x +60x = $126,000
=240x =$126,000 = 525 units
Ordinary computers = 4x
                 = 4*525
                 = 2,100 units
Therefore, The break-even point in units for ordinary laptops is 2,100 units.