Re: [計量] 請問兩題數學..
※ 引述《eadanlin (=口=)》之銘言：
: ※ 引述《retawaet (retawaet)》之銘言：
: : 2.At a sale, the cost of each tie was reduced by 20 percent
: : and the cost of each belt was reduced by 30 percent.
: : Column A
: : The percent reduction on the total cost of 1 tie and 2 belts.
: : Column B
: : 25%
: : 我寫A...可是答案是D
: : 為什麼無法比較呢?
: : 麻煩幫解惑 感激不盡
: 設領帶$a 打折後0.8a
: ..皮帶$b ......0.7b
: A: (0.8a+0.7b)/(a+b) = ??????
: 選D
Column A是The percent reduction on the total cost of 1 tie and 2 belts
所以應該是 (0.2a+0.3b*2)/(a+2b) = ??? 還是一樣兩個未知數~ 選D
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05/20 15:26, , 1F
05/20 15:26, 1F
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