请教PREP2中的两道题，谢谢

huangxiuying

138.   13412-!-item-!-187;#058&010022

A grocer stacked oranges in a pile.  The bottom layer was rectangular with 3 rows of 5 oranges each.  In the second layer from the bottom, each orange rested on 4 oranges from the bottom layer, and in the third layer, each orange rested on 4 oranges from the second layer.  Which of the following is the maximum number of oranges that could have been in the third layer?(C)

(A) 5

(B) 4

(C) 3

(D) 2

(E) 1

149.   15127-!-item-!-187;#058&010506

To determine her state income tax last year, Elena computed 5 percent of her gross income, rounded the resulting figure down to the nearest $100, and subtracted $50 for each dependent that she claimed.  If Elena's gross income was $34,500 and she claimed 2 dependents, how much did she determine her state income tax to be?(A)

(A) $1,600

(B) $1,625

(C) $1,650

(D) $1,675

(E) $1,700

139.   14556-!-item-!-187;#058&010396

If machine J, working alone at its constant rate, takes 2 minutes to wrap 60 pieces of candy, how many minutes does it take machine K, working alone at its constant rate, to wrap 120 pieces of candy?(B)

(1) Machine K, working alone at its constant rate, takes more than 5 minutes to wrap 60 pieces of candy.

(2) Machines J and K, working together at their respective constant rates, take 1 minute and 30 seconds to wrap 60 pieces of candy.

我觉得（1）也行啊

[此贴子已经被作者于2008-7-29 16:55:29编辑过]

cxfeng19

138.画个图就好想了

149. 34500/5=1725, rounded is 1700, 2 dependents就是100,所以就是1700-100=1600

139.仅仅是more than, 你怎么能知道machine K的certain rate? 

huangxiuying

谢谢哦，139题看错了，太粗心了

138题还是不太明白，能说详细些吗？谢谢