Use the information provided in each of the following independent situations to answer the questions. For each situation, briefly explain the reasoning behind each of your calculations.

a. Cash paid to suppliers for merchandise during a period was $37,500. Accounts payable decreased during the period by $3,000. Inventory increased during the period by $3,500. What was the cost of goods sold for the period?

b. Interest paid during a period was $4,000. Interest payable decreased during the period by $1,200. What was the interest expense for the period?

c. Cash flow from operations for a period was $28,000. Current assets decreased during the period by $6,000. Current liabilities decreased during the period by $2,000. What was net income for the period?

d. Cash collected from customers for a fiscal period was $27,000. Accounts receivable increased during the period by $3,000. What was sales revenue for the period?