不知怎么搞的..脑袋瓜顿在data sufficiency No.110

doadoa0820

真不好意思...自已因为之前太忙也没考好.. 现在又重新来过了..上来版 烦请大大帮个忙

想问一下各位大大们..这道ds的题目.. 我不知怎么搞的..顿在这道题..想也想不透了...

110.

Whenever Martin has a restaurant bill with an amount between $10 and $99, he calculates the dollar amount of the tip as 2 times the tens digit of the amount of his bill. If the amount of Martin's most recent restaurant bill was between $10 and $99, was the tip calculated by Martin on this bill greater than 15 percent of the amount of the bill?

<1> The amount of the bill was between $15 and $50

<2> The tip calculated by Martin was $8

Thanks!!

苡晴

snowfeb

(1) if the bill is 15, tip would be 2, 13% of the bill. if the bill is 20, tip would be 4, 20% of the bill. so, choice 1 is wrong.

(2) tip is 8, then the bill should be 4X. the highest percentage is 8/40=20%, the lowest is 8/49=16%. Both bigger than 15%. so, choice 2 is corrent

[此贴子已经被作者于2007-8-31 1:21:54编辑过]

doadoa0820

oh..i cc..Thanks!! Snow fed