※ 引述《pei33ho (酸)》之銘言：
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: The cost of a square slab is proportional to its thickness and also
: proportional to the square of its length. What is the cost of a square
: slab that is 3 meters long and 0.1 meter thick?
: (1) The cost of a square slab that is 2 meters long and 0.2 meter thick is
: $160 more than the cost of a square slab that is 2 meters long and 0.1 meter
: thick. 讣
說2m x 0.2m =2m x 0.1m + 160
令後者0.2m x 0.1m= Z 因為題目說價錢跟長度和厚度成正比
=> 0.2m:0.1m=2:1 => 2m x 0.2m= 2Z
2Z = Z+160 Z=160
問3m x 0.1m => 3m:2m= 3:2 => Z*(3/2)= 160*(3/2)=240
: (2) The cost of a square slab that is 3 meters long and 0.1 meter thick is
: $200 more than the cost of a square slab that is 2 meters long and 0.1
: meter thick.
同理 3m x 0.1m= 2m x 0.1m +200
只有一個比例變動 => 可依上法得結果
: 答案D
: 想問題目的意思是怎麼用數學式表示較正確呢?
: 查了精華區的討論總覺得還是怪怪的...
所以各自可提供解
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