Answer:
twig stands oak stands
sales price per unit $16 $43
variable costs per unit $3 $15
sales bundle = 4 twig stands + 1 oak stand
contribution margin per bundle = (4 x $13) + $28 = $80
contribution margin per unit = $80 / 5 = $16
total fixed costs = $400
break even point in units = $400 / $16 = 25 units
break even point in bundles = $400 / $80 = 5 bundles