With regard to accounts payable:

a$)$ Explain the significance of financing with accounts payable.

b$)$ Explain the rationale of taking a cash discount, such as $2/15,$ net$/45.$

c$)$ Additionally, determine the approximate balance of accounts payable, if a company stretches its payables to $60$ days from $45$ days and on average, they make purchases of $$1,000,000$ per day from their vendors.