xdjm们来帮帮忙了！prep-math-ps1-149

149. 15609-!-item-!-187;#058&010412(该题不明白为什么是0.7？我算的是0.8)
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

LZ注意这句either increased by $0.30 or doubled, whichever results in the lesser amount,指每一天都选较小的那个.因此second day:0.2 third :0.4 fourth :0.4+0.3=0.7而不是0.4*2

LZ的数学破解版在哪下的,可否告诉地址?

thanks a lot!

http://forum.chasedream.com/dispbbs.asp?boardID=34&ID=250699&page=1