Iadanza Corporation is a wholesaler that sells a single product. Management has provided the following cost data for two levels of monthly sales volume. The company sells the product for $195.70 per unit.

Sales volume (units) 6,000 7,000

Cost of sales $457,800 $534,100

Selling and admin costs $621,000 $639,100

a. What is the variable cost of sales?

b. What is the variable selling and admin costs?