does this question have a mistake? Because I have the solution, and it is solving for when a customer does give up an extra $30$ days to reap the benefits of the the $2\%$ discount. However, the question asks for when a customer takes the full $60$ days to pay, hence sacrificing their $2\%$ discount opportunity. $($QUESTION: does this question have a mistake? Because I have the solution, and it is solving for when a customer does give up an extra $30$ days to reap the benefits of the the $2\%$ discount. However, the question asks for when a customer takes the full $60$ days to pay, hence sacrificing their $2\%$ discount opportunity.$)$