图书馆对过期不还的书收取罚款, on the first day that book is overdue, the total fine is $0.10. For each additional day that a book is overdue, the total fine is either increased by $0.30, or doubled, whichever result in the lesser amount, what is the total fine for a book on the fourthday it is overdue?
whichever result in the lesser amount,什么意思?还有求的是第四天当天的罚款还是这四天的罚款?