The college library pays its student workers every 2 weeks. On payday, one of the workers receives a $270 check for the hours that he spends shelving books. The first week (7 days) after
payday the student generally does the majority of his shopping and spends an average of about
$25 per day. The next 5 days he spends an average of $15 per day, and the last 2 days before
the next payday he spends only $10 per day.