pp-t1-ds-57

[pauline_chiou]

57. 4795-!-item-!-187;#058&004223
During a sale, for each shirt that Mark purchased at the regular price, he also purchased a shirt at half the regular price. How many shirts did Mark purchase during the sale?

(1) The regular price of each of the shirts that Mark purchased during the sale was $21.50.

(2) The total of the prices for all the shirts that Mark purchased during the sale was $129.00.

答案是C，我是選E
我是想請問，因為題目是問how many....
但是這邊算出來可能有7,8,9,10,11這些可能
也算是成立嗎??
21.5x+10.75y=129
2150x+1075y=12900
當y=2,x=5 y=8,x=2
y=4.x=4 y=10,x=1
y=6,x=3

[Huang Hsin-Yi]

Dear 同學:

Y=1 , he also purchased a shirt at half the regular price

[pauline_chiou]

dear Huang Hsin-Yi大大
我了解您的意思，
只是這邊我不太懂
若是他有這麼多的可能，也可以成立嗎?

[Huang Hsin-Yi]

你沒了解我的意思
基本上,你式子列錯囉!!

[pauline_chiou]

阿!!
是說for each shirt that Mark purchased at the regular price, he also purchased a shirt at half the regular price.
所以(1)+(2)
(21.5+10.75)x=129.00
32.25x=129.00

[Huang Hsin-Yi]

bought X shirt , regular price P dollars

(1) X*21.5+1*21.5/2=total
(2) X*p +1*p/2 =129

(1)(2) you can get X

[pauline_chiou]

嗯...
題意不是說....每買一件 shirt at the regular price也會買一件shirt at half the regular price
@@是哪種解法?

[Huang Hsin-Yi]

我的理解是:
每一件T-shirt他都買正常價,他也買一件半價
但不是你說的
....每買一件 shirt at the regular price也會買一件shirt at half the regular price

[pauline_chiou]

嗯嗯
謝謝Huang Hsin-Yi大大
看來我的閱讀能力要再加強.....

[Philosophia]

～刪～

自己想通了～

[canadacom_orig]

這樣他買了 一件10.75

且總共花了129

(129-10.75)/21.5 不是除不盡嗎?

請解惑...

[Philosophia]

這題我比較傾向 for each shirt that Mark purchased at the regular price, he also purchased a shirt at half the regular price.

如此所得到的就是整數解了～