Question number 6 I need help

Answer:
6. a)
total fixed costs = $600,000
product mix:
1 Diablo: 2 Call of Duty: 3 Sekiro: 4 Starcraft II
Contribution margin per unit:
Contribution margin per product mix = $33 + (2 x $31)) + (3 x $21) + (4 x $11) = $172
break even number (in product mix) = $600,000 / $172 = 3,488.37 ≈ 3,489 product mixes
6.b)