[問題]GWD01-30(31套版)

由 **Ricky1120** » 2006-10-18 00:36

30.Joanna bought only $0.15 stamps and $0.29 stamps. How many $0.15 stamps did she buy?
(1)She bought $4.40 worth of stamps
(2)She bought an equal number of 0.15 stamps and $0.29 stamps

這題我選C 但答案是D 請各位大大幫忙了!

由 **steven** » 2006-10-19 02:13

這題答案應該有錯答案是A
0.15跟0.29互質所以用A就可以解出買0.15跟0.29的都是10張

由 **Ricky1120** » 2006-10-19 12:51

0.15X+0.29Y=4.4
請問為何互質就帶的出X=Y=10?
是要一個一個帶嗎?

由 **steven** » 2006-10-22 00:24

我只能說這題是特例了只有這唯一解所以在算時要小心點有時間的話最好驗算看看

[問題]GWD01-30(31套版)

[問題]GWD01-30(31套版)

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