can someone explain step by step why this is the answer and write the absorption costing formula too?

$40 Garrett, Inc. produces surfboards. Below is cost data for Garrett, Inc. Selling price per unit $200 Direct materials $60 Direct labor Variable factory overhead $30 Total variable cost $130 Fixed factory overhead $500,000 Selling costs (fixed) $100,000 Adminstrative costs (fixed) $200,000 Assuming there are 300 units in finished goods ending inventory from a production run of 50,000 units, what is the cost of this inventory using absorption costing? Submit No. The answer is $42,000. We found from a previous question that the cost per unit using absorption costing is $60+ $40 +$30 +$10 = $140. $140 X 300 units = $42,000. You have completed this exercise