D Spare Pte Ltd. produces sells tool kit sets for people to Do It Yourself, below are details

of the tool kit set:

Selling price per set $100 Variable cost per set: Bolts and nuts $45 Casing and carton box $ 2 Labour cost $ 1 Sales commission $ 2 Fixed manufacturing cost per year $50,000 Customer service and office expenses per year. $100,000 Sales in 2020 5,000 sets