PREP-PS1-149

EricMIT

149.
                15609-!-item-!-187;#058&010412

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

我选择C，答案给的B；

我的计算方式：

the total fine is increased by $0.30：第一天0.1，第二天0.4，第三天0.7，第四天1.0

the total fine is doubled：第一天0.1，第二天0.2，第三天0.4，第四天0.8

怎么算也不应该是B啊

请NN指点，BOW～～

cjwbhu

应该是在每日都会面临是double还是加0.3的选择，这样做出来之后就是0.7

EricMIT

哦。明白了。谢谢！

阅读不过关啊。

陷阱多多......

jockey829

还是不太明白LS的LS~~

EricMIT

应该是在每日都会面临是double还是加0.3的选择

第一天0.1，第二天0.2，第三天0.4，第四天的时候因为要最小化，所以选择0.4+0.3=0.7，而不选择double