$6\mathrm{.}22$

A college student, Brad Worth, plans to sell atomic alarm clocks with CD players over the internet and by mail order to help pay his expenses during the summer semester. He buys the clocks for $$32$ and sells them for $$50.$ If payment by check accompanies the mail orders $($estimated to be $40$ per cent of sales$),$ he gives a $10$ per cent discount. If customers include a credit card number for either internet or mail order sales $(30$ per cent of sales$),$ customers receive a $5$ per cent discount. The remaining collections are estimated to be:

$\backslash$table$[[$One month following,$15\%$