$20.$ You have dormised that you avera collection times is $10\mathrm{.}1$ days it takes the firm $4\mathrm{.}5$ days to prepare and mail out all the monthly statements to your customers who all pay properly upon receipt on average the mail between your firm and your customers is $3\mathrm{.}4$ days and your customer checks taken average of two days to clear the bank how long is it taking your firm to process the payments from the customers?