Mark Cameron owns a store that sells greeting cards. On average, cards cost $2 each, but some are cheaper ( $5 a dozen) and some are more expensive ( $5 each). The direct cost of cards is expected to be 50% of the selling price. In the month of January, the following data apply: (i) Inventory of cards at cost on January 1:$1,500. (ii) Cards purchased in January: $13,500. (iii) Inventory of cards at cost on hand January 31:$5,000. (iv) Sales in January: $20,000. Required (a) Calculate the cost of goods sold in January. (b) Calculate the gross margin for January. (c) Calculate the gross margin as a % of sales for January. (d) Is there a problem with the gross margin \%? (e) Is there a problem with the closing inventory level