数学题

dreadpower

25.A certain library assesses fines for overdue books as follows. On the first day that a

book is overdue, the total fine is 0.10. For each additional day that the book is overdue,

the total fine is either increased by 0.30 or doubled, whichever results in the lesser

amount. What is the total fine for a book on the fourth day it is overdue?

A 0.60
B 0.70
C 0.80
D 0.90
E 1.00

答案为B。我选C.

missouyang

25。好好读读这句话 For each additional day that the book is overdue, the total fine is either increased by 0.30 or doubled, whichever results in the lesser amount.

过期一天的罚款是0。1元，过期二天的罚款是0。2＝0。1×2元（不能选0。1＋0。3元，因为前一天的罚款的2倍比0。1＋0。3要小），过期三天的罚款是0。4＝0。2×2元（也不能选0。2＋0。3元），第四天的罚款是0。7＝0。4＋0。3元，故选B。