1. Tom buys a dress and a blouse in a boutique.She has a coupon which entitles her to but a piece of good with 20% discount.If she used the coupon when she buys the blouse,she has to pay 230 dollars.If she used the coupon when she bought the dress, she would only have to pay 220 dollars.What is the original price of the blouse?
2.Tom thinks of a postive interger N and writes down all its positive multiples less than 100.She finds that the digits "8" occurs exactly four times.Find the value of N.
3.Tom uses 7 pieces of rectangular cardboard with length 4 and width 3 to form a big rectangle.Given that there is no overlapping of cardboard,find the sum of all possible values of the perimeter of big rectangle.
要有答案&WHY.答得多少得多少,謝^
F.1 奧數題,急
2010-12-11 2:17 am
回答 (3)
2010-12-11 11:27 pm
✔ 最佳答案
1.1002.6
3.150
2010-12-15 11:13 pm
1)devide 230 by (1-20%)because:
let the orginal price of the blouse be A dollars
A times 1-20%(cost price after using the cupon)=230
A=devide 230 by (1-20%)
2)can you use chinese pls
3) first, if Tom only use 7 piece of cardboard, there should only be two possible.
4 times 7 times 2 plus 3 times 2=62
or
3 times 7 times 2 plus 4 times 2=54
because you can only use the cardboard to form the rectangle in a straight line like this
圖片參考：http://happyhappyplace.yolasite.com/resources/happym.jpg
2010-12-15 15:15:21 補充：
1)287.5 dollars
2010-12-15 15:17:20 補充：
3)sorry i've not look at the question carefully.the sum of them should be 62 plus 54 equals to 116
let the orginal price of the blouse be A dollars
A times 1-20%(cost price after using the cupon)=230
A=devide 230 by (1-20%)
2)can you use chinese pls
3) first, if Tom only use 7 piece of cardboard, there should only be two possible.
4 times 7 times 2 plus 3 times 2=62
or
3 times 7 times 2 plus 4 times 2=54
because you can only use the cardboard to form the rectangle in a straight line like this
圖片參考：http://happyhappyplace.yolasite.com/resources/happym.jpg
2010-12-15 15:15:21 補充：
1)287.5 dollars
2010-12-15 15:17:20 補充：
3)sorry i've not look at the question carefully.the sum of them should be 62 plus 54 equals to 116
參考: myself
2010-12-11 3:00 am
1. use equation,
let x dollar be the blouse
(1-20%)x=230
80%x=230
x=287.5
therefore,the original prize is 287.5 dollar.
formular of the original prize:(1-D%)x=selling prize
let x dollar be the blouse
(1-20%)x=230
80%x=230
x=287.5
therefore,the original prize is 287.5 dollar.
formular of the original prize:(1-D%)x=selling prize
參考: me
收錄日期: 2021-04-23 20:48:53
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101210000051KK00874